Page:Hardwicke's Science-Gossip - Volume 1.pdf/27

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Jan. 1, 1865.]
SCIENCE-GOSSIP.
11

who are observers of nature, in its minute and more obscure forms, and who, amidst the busy cares of life, have been content to leave for a time the ceaseless anxieties of £ s. d. and contemplate the world which is around them.

In the month of September last, the weather having been exceedingly humid and oppressive for several days, we observed, as the dusk of evening approached, that an unusual number of unhappy flies had come to an untimely end in various parts of the house, not on the windows only, but, as a closer examination showed, they were tightly fixed to the wainscoted walls and other smooth and polished surfaces. Varnished and glass-like objects had been generally selected, although rarely rougher surfaces had sufficed, the smoother being evidently preferred as being probably better adapted for adhesion. We could remember the time when we had seen dead flies sticking to the windows, surrounded by a little cloud, which in our ignorance we then thought was only dust; but the time arrived when we learnt that the so-called dust was a vegetable growth, and we were now aware that these flies had died in consequence of the overpowering attack of a fungus, to which they had succumbed. The curiosity which at times had possessed us so strongly as to make us look with longing eyes at the victims on our neighbour's windows, and wish we might be allowed to cut out a small piece of his glass, say 'three inches by one,' induced us now to investigate a little more closely than hitherto the humble subjects of our remarks.

A diligent search rewarded our endeavours, for after some time had been spent in watching our small friends, we perceived one which was not so lively as its companions, but rather in a semi-torpid condition, which had extended its proboscis and by aid of its two fore feet appeared to be clutchin the glass with a spasmodic effort. Here then, at last, was an opportunity of obtaining a good specimen for futher examination. One minute sufficed to fetch a slip of glass, and then, carefully placing the fly on the centre of it, we were gratified at beholding the victim again extend its proboscis, and, with the assistance of all its legs, resume the position in which we first saw it. For security we placed a large bell-glass over it and resumed our hunt. Another "incurable" quickly met our fond gaze, and in its turn was placed on another glass slide. It proved as docile and tractable as its fellow, and readily adhered to the glass. Feeling we were now sufficiently supplied, we proceeded to watch with some attention, but were not enlightened by any movement on the part of the patients. Unlike the Davenport Brothers, they were evidently unable to release themselves from the bonds which restrained them, so we left them quietly for an hour, and at the end of this period observed a dulness on the glass, though it was so slight as not to be easily discernable. At the end of two hours, another pper revealed the fact that what had appeared as only a dulness before had now developed to a distinct white cloudiness, which extended for a short space from each side of the abdomen, and gave evidence of forthcoming work for the microscope, as soon as the slides might be safely moved, without risking the somewhat fearful calamity of disturbing the innocent subjects of our notice. We therefore left them for the night, full of hope that the returning day would reveal a further development of this interesting parasitic plant.

With the "cock's shrill clarion" we awoke on the following morning, and no follower of the chase ever left his bed-chamber more eager for the sport team we were to ascertain the state of our prisoners; nor were we disappointed in our hopes as to the result of the last eight hours. The flies were dead; but we did not grieve, on the contrary, we rather preferred it, for it promoted the object of our inquiry, by rendering the vegetation of the plants more complete, as was proved by the first glance we took at the glasses. The white dust now extended to the edges, although not at all in a regular and even film, but seemed radiated in waves more or less opaque, while the flies had maintained their original position and consequently had all the appearance of life.

Desirous to see the end of this parasitic growth, we refrained from disturbing it until more than a week had elapsed, when we submitted one of the slips to examination under the microscope. We then perceived that what appeared to be a white dust, consisted of innumerable small disc-like spores or seeds, which were flat and circular, each having a nucleus and a few markings or rays extending from the centre to the edge, so that they might be familiarly compared to cart-wheels in appearance. The fly itself also proved an interesting subject for examination, as the hairs which covered it in all directions were beautifully decorated with snow-white globules, like bunches of grapes. The wings, legs, and proboscis were likewise dotted with similar spores, while they were abundant at the less horny parts, between the plates of the abdomen.