HAilDWiCKE'S SCIEKCE-GOSSIP. 



THE SMALL EGGaR-MOTH. 



TT seems advisable to say a few words upon a 

 -^ correspondence which has been going on for 

 some time on the larva and pupa states of Erio- 

 gaster Icuiestris (the small Eggar-moth). Several 

 writers complain that they cannot obtain pupfe, and 

 that the larvae die when fall-fed. I think that this 

 must be owing to a want of attention to one or two 

 peculiarities in their habits. One is well known. 

 As soon as they emerge from the e^g, they go to 

 work and mutually construct a silken tent round 

 the twig upon which the eggs have been laid. This 

 habitation is added to as the larva; grow, and into 

 it they retire when not engaged in feeding. A 

 second habit is not so well known,— that of basking 

 in the sunshine upon the outside of this web. Now 

 if, when the larva? are collected, their nest is not 

 also taken and carefully kept in contact with their 

 food, they will hardly ever do well; neither do they 

 like to be deprived of sunshine. 



Some years ago I brought home a large nest of 

 young larvse, stood the branch in a jar in an un- 

 occupied room, put fresh branches of blackthorn or 

 whitethorn into other water-jars close by, arranging 

 that the bushes should touch each other, and sup- 

 plied fresh branches every two or three days, as 

 they withered or were stripped. Li this way the 

 larvse fed well and enlarged their nest to an 

 immense extent as they grew, and it was curious to 

 see them when, at a certain hour in the day, the 

 sun shone upon the nest, crowding upon the out- 

 side of it, squeezing in between each other like pigs, 

 and lying so close together that a pin could hardly 

 be put between them without touching. I think, 

 however, that they did not get enough sun; for 

 although many spun up in reasonable time, others 

 continued feeding till quite late in the summer, 

 and as, on arriving at full size and assuming their 

 handsome skins, they had become erratic, and re- 

 quired to be kept at home with gauze bags, my 

 patience got exhausted, and having a hundred or 

 two of pupse, I turned the rest out. About this 

 matter of the long duration of the pupa state : it 

 really is nothing new. It was noticed in " West- 

 wood and Humphrey's British Moths " more than 

 thirty years ago, and most likely long before, but I 

 have not books at hand. 1 did not expect my 

 moths out the next spring; but one specimen ap- 

 peared, and with proper treatment, I feel sure that 

 many more would have come out. The second 

 spring 1 thought of the advice of a writer in the 

 E/domoloffiai's Weekli/ IiitelUgencer, years ago, 

 <nud brought down my pupa; one mild day in the 

 middle of February, and put them on to the mantel- 

 piece. 



They acknowledged the attention at once, and 

 emerged by dozens. The next year I did the same, 

 and some more came out; but since that only a 



stray specimen or two have appeared, and 1 have 

 now been breaking open the sound cocoons, and 

 find that great numbers of the moths have perished 

 in the pupa when fully formed and coloured; and 

 this I have no doubt occurred in the first spring, 

 when they had not suflicicnt M'armth to enable them 

 to burst the pupal envelope. 



There is another point — the curious double co- 

 coons, from which nothing ever emerges. These 

 are not divided inside, but are formed by two larva; 

 uniting their ell'orts, and producing a broad cocoou 

 the size of the ichole material of two single ones. 

 Thus, two sides being saved, it is larger than the 

 two single ones would be. 



Could anybody expect anything to emerge fron\ 

 this ? In the first place, a larva, when assuming 

 the pupa state, requires the most perfect liberty 

 from interference or annoyance. How, then, could 

 either of two larvse, wriggling off their skins in the 

 same cocoon, be expected to succeed? The only 

 chance would be by one dying in the larva state. 

 But then the survivor would have too much room, 

 — would have, in fact, no " purchase " anywhere by 

 which to burst open the lid of tlie cocoon. 



Fortunately an example occurred among my lot ; 

 and I found, on o;;euing it, that one larva shrivelltd 

 up without attempting to cast its skin, that the 

 other changed, and in due time the moth emerged 

 from the pupa skin, but never left the cocoon. I 

 found it crumpled up and dead, of course. To this 

 large cocoou three others were slightly attached : 

 from one the moth emerged, and in the other two 

 they died when ready to emerge from the pupa. 



C. G. Bareett. 



NEW SPECIES OF ROTATOllIA. 



By F. Collins, M.D. 



PREVIOUS lo 1S67, while residing in the parish 

 -'- of Sandhurst, Berkshire, it was my fortune to 

 meet with several uudescribed species of Rotifers. 

 Presuming that some of the readers of Science- 

 Gossip may be interested in that very attractive 

 group of animalcules, I have forwarded for their 

 perusal the following copy of my rough notes, 

 written five years ago, during the time I was em- 

 ploying some of my leisure hours in studying these 

 very beautiful and interesting creatures. 



Melicerta social is. — Tube irregular in shape, 

 built of large yellowish-brown, granular, egg-shaped 

 pellets, which are heaped up into the form of a 

 tube, without any regard to symmetry. The rota- 

 tory disc is divided into two lobes, the anterior 

 division being, as is generally the case, much deeper 

 and more marked than the posterior or dorsal divi- 

 sion. The eyes are cervical, two in number, and of 

 a pale rose-colour. The maxillary bulb is placed 

 high up in the neck. The two hooks seen iij 



