HARDWICKE'S SCIENCE-GOSSIP. 



39 



ZOOLOGICAL NOTES FOR 1884. 



LOOKING over my last year's notes, I find one 

 or two which may be worth preserving. My 

 knowledge of the literature of the subject is not large 

 enough to enable me to judge of their general value. 



(a.) Late in the summer, the vital fluids of insects 

 seem to become inspissated, in the same way as those 

 of leaf-petioles. Hence they may be touched when 

 at rest, before able to summon sufficient energy for 

 flight. 



(/'.) During the summer, I observed in some marshy 

 ground by the upper Thames that an atrous Limax 

 was attached profusely to the stems of a rush, whose 

 black flowering spike was distantly similar. Is this 

 mimicry, and if so, to what end ? 



(c.) On February 15th, after a fire, for the first time 

 since the autumn, 4iad been alight an hour or two in 

 a room, a blow-fly emerged from its pupa-case, and' 

 stayed in the room for four days, although doors and 

 windows were constantly open. The cold air would 

 seem to have formed an impenetrable barrier. 



(</.) Out of an incomplete brood of P. rapae, which 

 perfected early in May, 9 were ^the last to emerge, 

 and d the first, the percentage of <? was 22, and in 

 the course of a confinement of some two or three 

 weeks, all of them died, without having made any 

 attempt at coition, the 2 surviving hardily. This 

 would point to d as the subjected factor in lepidop- 

 terous social life. 



(e.) A lepidopterous larva, not full-grown, having 

 been inadvertently kept in an air-tight box for 

 24 hours, commenced to pupate, with the apparent 

 object of preserving its life. When released, and 

 placed with its food-plant, it still proceeded with the 

 work of pupation. Bees confined under similar 

 circumstances having died, it would appear that 

 larvra respire less abundantly than perfect insects, 

 and pupae less still, if at all. Also that, when the 

 process of pupating has begun, some internal re- 

 arrangement of the larval parts takes place at once 

 (cf. development of spinnerets), as a result of which 

 larval growth cannot be resumed. 



(_/".) An unfortunate and unintentional experiment 

 with a T. pronuba would show that the asphyxiating 

 property of hydrocyanic acid fumes may be overcome 

 if brought into contact with the poisoned specimen, 

 especially if of robust habit in time. This may serve 

 as a hint to keep up the strength of cyanide bottles, 

 in order to prevent needless cacopathy. Thus this 

 specimen, after being pinned out, was found three 

 days after fluttering in full vigour, its wings being 

 withdrawn from the pressure of the setting slips. 

 Again,'a Spilosoma menthastri laid 160-170 eggs after 

 being stifled and pinned out, although this very 

 common phenomenon is no proof of return to 

 consciousness. 



{g.) Observed a solitary bee on the wing one mile 

 out at sea off the Norfolk coast. It did not secure 



the opportunity to rest afforded by the crab-boat 

 whence it was seen. It being comparatively calm at 

 the time, the journey must have been to some extent 

 voluntary. 



(h.) In the end of June a pupa of C. ligniperda. 

 broke through its cocoon, which was buried in a 

 flower-pot, worked its way some 3 inches to the 

 surface, exserted the head-parts, leaving the abdomi- 

 nal parts of the case firmly embedded in the earth, 

 and emerged in this way. Another specimen, whose 

 cocoon was half-exposed, fixed its pupa case midway 

 in the mouth of the cocoon while it emerged. 

 Neither the uplifted case, nor the half-protected 

 cocoon, was broken or crumpled by the weight of the 

 moth. This is an interesting instance of adaptation 



to circumstances. 



Ernest G. Harmer. 



NOTES ON HYDRACHNIDES. 



MR. DRAPER'S beautiful illustration of Lim- 

 nesia reminds one that a monograph of the 

 British fresh-water mites still remains to be written, 

 and therefore a description of the peculiarities of the 

 sub-families Limnesia and Eylais, may be of some 

 interest to the readers of Science-Gossip. These 

 mites belong to Koch's second division Hydrachnides, 

 and with regard to Limnesia, he says, " They are to 

 be found in large and small pools, tolerably common, 

 swim quickly without soon tiring, and are the richest 

 in species of all the four-eyed water-mites." He 

 describes twenty species : of these Hermann had 

 previously described two, and Midler three. The 

 mite Koch takes as his type of the species is 

 Limnesia fulgida, and is, I believe, the one figured 

 by Mr. Diaper. The body is oval, smooth, very 

 convex, of a beautiful, somewhat transparent scarlet 

 colour, varied with darker markings produced by the 

 caeca. Eyes four, in two pairs, each pair rather far 

 apart, but the ocellus of each pair near together, 

 forming an oblong figure thus — : : Palpi and 

 legs blue — the four hind legs are well endowed with 

 long swimming hairs, and the tarsal joint of the hind 

 legs is without claws. All the legs are used in 

 swimming. The sub-family Eylais contains, ac- 

 cording to Koch, but five species, and he remarks 

 that they differ very little from each other. Eylais 

 extendens, first described by Latreille, is the type 

 species. The body is oval, but much broader behind 

 than before, only slightly convex ; the skin velvety ; 

 the colour vermilion. The eyes are placed rather 

 near together, forming almost a square thus — : : and 

 are arranged on a plate of chitin or thickened skin. 

 The palpi and legs are of the same colour as the 

 mite ; the last pair of legs has no long swimming 

 hairs, consequently when the mite swims, these legs 

 are not used, but dragged after it, in a peculiar and 

 very characteristic manner, which alone, at once 



