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VOL. XXIV NO. 13, October 16-31, 2014
Observations on a 'troublesome insect'

Pages from History' by Dr. A. Raman Charles Sturt University Orange, New South Wales Australia

On the metamorphoses of the mosquito by William Gilchrist, a medical officer attached to the Madras Medical Establishment, Madras, was published in the Madras Journal of Literature and Science in 1836. Gilchrist’s observations were made in Hoonsoor (now ‘Hunsur’, Karnataka), a remote village in the Madras Presidency in the 1820s, when magnifying optical instruments were crude and primitive even in Europe. Gilchrist made the observations approximately six decades before Ronald Ross established the connection between the mosquito and malaria and 70 years before papers on Indian mosquitoes were published in the early 20th Century by George Giles, who started his studies with Ronald Ross in Calcutta at the turn of the 19th Century.

From larval form to 21-day growth, as sketched by Gilchrist. (Note: the horizontal line is the water level in the glass.)


Almora-born Ronald Ross’s discovery of the developmental stages of Plasmodium (Protozoa: Haemosporida:
Plasmodiidae) in the gastrointestinal tract of an anopheline mosquito, when he worked as general-duty medical officer at an army station in Begumpet, Secunderabad, in 1893-1895, led to the finding that malaria is transmitted by Anopheles, for which he was awarded the Nobel Prize for Physiology in 1902.This finding led to launching mosquito-management measures to combat the deadly disease not only in India, but also elsewhere. Ross was led to consider mosquitoes as a possible agent in the transmission of the malarial parasite by the work of a Dr.  Manson.

Around the end of 1870-early 1871 Patrick Manson settled in Amoy, a port town in China, where he had occasion to treat several people suffering from elephantiasis. Towards the end of 1874, Manson returned to the UK and explored the causes and the spread of elephantiasis. He developed the theory of mosquito transmission of the disease. Ross, who had got interested in malaria in 1892-1893, met Manson in England in 1894, and was shown the stained blood smears that included malarial parasites. This was when Ross saw malarial parasites – for the first time – through a microscope. Manson impressed on Ross about the possibility of the mosquito being the carrier and intermediate of organism. These conversations with Manson stimulated Ross to tackle the malaria challenge in earnest. In 1898, Ross showed that the mosquito was the malaria vector.

But before Ross established the mosquito’s role in malaria-parasite transmission, there appeared in the Madras Journal of Literature and Science an article by one W. Gilchrist (July-October 1836 issue), that is nearly six decades before Ross established the link between mosquitoes and malaria,. Robert Cole of the Madras Medical Establishment and the editor of volume 4 of the MJLS wrote:

“.... several observations are perfectly original, as far as we are able to ascertain, and would entitle the paper to admission into the pages of any Journal devoted to matters of science. Moreover, whether novel or not, the highly intelligent author is entitled to the full credit of independent observation, not having access to books on the subject, in the retired station (Hoonsoor) at which he is resident; and we gladly, therefore, give a place to the article not only on account of its intrinsic value and interest, but as an incentive to others, to institute observations and inquiries in the wild field of nature, spread out before them on all sides, and inviting their attention.”

William Gilchrist was a Glasgow MD & CM* who worked with the Madras Medical Establishment. From 1850 to 1855, he was the Professor of Medicine at Madras Medical College.

Besides being a surgeon by training and practice, Gilchrist seems to have been an enthusiastic veterinarian as well, because he has documented treatment methods for diseases afflicting the elephant, camel and bullock. In addition, there are two papers by him on self-registering barometers published in MJLS (Gilchrist 1837, 1838), which indicate his scientific versatility, extending beyond his medical knowledge and interest.

At the start of his note on the mosquito, Gilchrist refers to it as a ‘troublesome insect’, implying it is a nuisance. His observations were made at one time – with no replications. He alludes to using a microscope to observe the eggs, but does not provide any detail of either the scope or the power of the objective pieces he used. He estimates the number of eggs he saw under the scope (‘...not fewer than one hundred eggs...’), but has measured the size of the egg cluster (‘... did not exceed three-twentieths of an inch in length, and about one-twentieth of an inch in breadth.’). He also provides measurement of each egg (‘... 1-40th of an inch long ...’) and provides details of the gross morphology of the eggs.

He also describes some of his ‘experiments’. He introduces eggs (referred as ‘ova’) into a ‘tumbler’ of water and refers to the colour changes he saw. In 2.5 days, he saw swarming animalculae (the larval forms). He includes a line sketch of the larval form – described by Gilchrist as ‘newly hatched insect’.

Gilchrist later refers to his trials to feed the larvae with vegetable crumbs (‘vegetable matter’) which were ‘consumed voraciously’; he also offers another useful remark: ‘They did not, however, entirely confine themselves to a vegetable diet.’

Gilchrist indicates that insects remain in this stage for 48 hours. Then, his words offer an impressive reading.

“This, in due course, bursts, when the winged mosquito draws itself out, stands on the surface of the water a few minutes, to dry and expand its wings, on which it presently proceeds to a dry situation. I observed several undergoing this change.”

We go on to learn from him that the mosquito is the most prolific insect and that far away stagnant water, such as that of tanks etc, is necessary for its propagation. All such stagnations ought to be kept as far away as possible from dwellings; thereby we are more likely to enjoy “an immunity from their annoyance.”

Gilchrist’s note in the MJLS (1836) excitedly made me think that his note was the earliest public documentation of the developmental stages of mosquitoes, but that excitement was short-lived. As I dug into the literature on the history of mosquito biology, I found that the earliest recording of details on the egg, larval and pupal stages, supported by elegant sketches, was that of Johannis Swammerdam in Utrecht (Holland) in his magnum opus, Historia Insectorum Generalis (1669). American mosquitologist Harry Stage has chronicled historical searches done in mosquito biology in a global context and refers to the work of the Italian Jesuit Filippo Bonanni (1638-1723) and to that of René Antoine Ferchault de Reaumur (1683-1757).

Notwithstanding the fact that the Gilchrist note does not outline anything new, the effort made by Gilchrist is appreciable, given that his observations of mosquito development were made by examining them in extremely modest conditions and facilities. On three scores, Gilchrist’s note is worthy of remembering: (i) the insect he observed appears to be an anopheline taxon, whereas much of the European work done prior to him refer to culicine taxa, (ii) Gilchrist provides reasonably accurate details of time lengths of developmental process durations and (iii) his notes pertain to an Indian mosquito taxon, reiterating the biology of a subtropical-tropical species.

In the late 19th and early 20th Centuries, at least three British medical officers of the Indian Medical Service shine in the chronicles of mosquito biology: George Michael James Giles (Lieutenant Colonel, 1853-1916), Sydney Price James (Lieutenant Colonel, 1870-1946) and William Glenn Liston (Lieutenant Colonel, 1873-1950). Giles started mosquito studies in 1899 with Ronald Ross; he published 18 papers on mosquitoes in India and from nearby countries.

One serious weakness in Gilchrist’s note is that it does not refer to any of the earlier publications on mosquito metamorphosis; it is presented as a note based on casual observations; MJLS editor’s note was, in high likelihood, intended to justify the publication of a casual, unreferenced note from Gilchrist – (Excerpted from a paper in Oriental Insects)

Heritage workshop held for Corpn. Teachers

DakshinaChitra, along with the Education Commissioner’s
Office of the Chennai Corporation, has started a series of workshops for the teachers of the schools in Chennai. Two such workshops have been conducted and teachers from the various zones of Chennai have been participants. The one-day workshop introduces topics such as heritage, culture, craft, folk performances, etc. to the teachers. It also aims to give know-how on practical implementations of ideas such as conducting heritage clubs in schools, puppets as teaching aids, etc. Dr.  Suresh from INTACH was the external resource person for the first two workshops which are conducted free of cost. The workshop also includes lunch, refreshments and a guided tour of DakshinaChitra.

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OUR ADDRESSES

In this issue

Some old rules for new areas
Madras Landmarks - 50 years ago
Swachh Chennai – Can it work?
Observations on a 'troublesome insect'
Encounters with mongooses
When Radio, Film & TV arrived
During those days of dissection
The stars in Gandhi Nagar

Our Regulars

Short 'N' Snappy
Readers Write
Quizzin' With Ram'nan
Dates for Your Diary

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