110 



HARDWICKE'S SCIENCE-GOSSIP. 



otherwise, could these sensitive parts be wounded 

 with perfect unconsciousness at the time to the 

 victim ? The illustration is three inches in length, 

 and represents about one-eighth part; we may 

 then form a notion of the extension and tenuity of 

 this delicate trunk by recollecting that, on this 

 scale, and iu this proportion, it would reach a length 

 of two feet ; the breadth being, on an average, 

 about half an inch. The poison of the Gnat is acid, 

 like that of other insects and of reptiles, and the 

 best remedy for it is the speedy application of an 

 alkaline solution ; a little carbonate of soda will do 

 very well; and where the swelling is persistent 

 (and it sometimes lasts a week) and the wounded 

 part out of sight, a little of this in powder made 

 into a plaster with soap, and kept on for some time, 

 is a good domestic remedy. But prevention is better 

 than cure. Tourists in the South of Europe and 

 elsewhere will do well to drive out the Gnats. On 

 retiring to rest, set the light in the passage or an 

 adjoining room, and systematically, commencing at 

 the further end, rouse up the troublesome intruders 

 by beating the walls and shaking the curtains, and 

 so urge them through the door, which may then be 

 shut. The few stragglers remaining on the walls 

 may be detected with a light and easily despatched. 

 If but one remains, it will fly straight to its prey 

 through the dark, and there will be nothing for it 

 but to rise, strike a light, and secure it ; unless by 

 a happy blow in the dark, as the twang nears your 

 face, you may have him (or rather her, for only the 

 females are so intrusive and bloodthirsty) safe and 

 sure between the palms of your hands. Your sleep 

 will then be undisturbed ; and although this may 

 seem a great trouble, it is better than a dizzy head, 

 a swollen face, and knotted ears, the' ill-concealed 

 smiles of the coffee-room in the morning, and the 

 condolence of your friends. S. S. 



NOTES ON ROTIFERS. 



/^vN the 2Sth of September I brought home a 

 *-* bottle of water from a pond in the neighbour- 

 hood for examination. The first drop, with a small 

 particle of weed, supplied, besides many stentors, 

 rotifers, and vorticels, a very large specimen of 

 Hydra viridis. He was full of buds — like cups — 

 buds down his body, buds along all his arms ; he 

 was more cumbered with children than the tra- 

 ditional lady of the shoe. 



The next dip furnished two or three specimens of 

 Melicerta ringens. This interesting individual, 

 who builds a house of cricket-balls, has been so well 

 described that I shall not venture to say much 

 about it. It may, however, interest you to know 

 that I kept them alive for several days, from Sep- 

 tember 28 to October 2. Such minute creatures I 

 prefer to examine on a glass slide with a thin cover- 



ing-glass over them, which gives them sufficient 

 room for expanding themselves freely, and admits, 

 at the same time, the use of a -ro objective. On 

 one occasion the Melicerta having got under a piece 

 of weed, I took off the covering-glass, and in re- 

 placing it broke off a large portion of the tube, 

 without, however, damaging the animal : this acci- 

 dent caused him much trouble ; he worked hard all 

 day, and afforded excellent opportunities of examin- 

 ing the method of making and depositing the pellets 

 of which his house is built. 



So far as I could discern, by using different 

 powers (up to ~o with C), the pellets, when first 

 made, are all more or less round.' If they become 

 hexagonal it is only by subsequent pressure ; those 

 in the lower part of the tube are hexagonal (mostly) ; 

 those in the upper not so. 



By the afternoon the Melicerta had added several 

 rows to his dilapidated w"alls, and by six o'clock the 

 house was much enlarged. 



It is not easy to trace the process of receiving, 

 smashing up, manufacturing, and placing the pellets, 

 from beginning to end. 



So far as I could form an opinion, it seemed to 

 me that the particles received througk the mouth 

 passed at once to the gizzard to be smashed up, and 

 were thence conveyed to an organ, called, I believe, 

 by Mr. Gosse, from its function, the IC mill," and 

 from its shape, " the ventilator," to be formed, by 

 rapid rotation and mixing with some viscid fluid, 

 into balls. 



It seemed as if this organ rejected some particles 

 presented to it, which were shot out with force. 

 The gizzard sometimes worked slowly ; the " mill " 

 appeared to be always going at a uuiform speed ; 

 in shape it is something like the openings in the 

 pygidium of a flea. 



By the evening of September 30 the house was 

 finished. October 1, examined the Melicerta with 

 1 inch and B, and •£; inch and B, and black ground 

 condenser : most lovely ; the fans transparent, like 

 pearl. It is impossible to conceive anything more 

 beautiful than the appearance of the Melicerta under 

 this method of illumination — unless it be that of a 

 forest of Eloscularia, presently to be described. 



There was a constant rush of particles into the 

 mouth at the bottom of a funnel defended by a pro- 

 jecting lip, in shape like a sausage, and from the 

 mouth to the mastax ; a constant rejection of 

 particles, and a transference of some to the "mill," 

 whose working under this illumination is particularly 

 distinct. 



November 11. — Examined several specimens of 

 Melicerta and of Floscidaria ornata and cornuta. I 

 found considerable difficulty in distinguishing these 

 two forms. 



With the black ground condenser the sight was 

 very beautiful. Do not think I am exaggerating 

 when I tell you that there were literally hundreds 



