36 



SCIEXCE- G OS SI P. 



NOTES ON SPINNING ANIMALS 



By H. WAIJJS Kew. 



I. A Centipede's Web. 



AMONG spinning Myriapodsthe most notorious, 

 perhaps, is the little slender, elongated 

 centipede. (Teojrfnhi*. whose web. much enlarged, 

 is shown in the accompanying illustration. The 

 drawing is copied from a figure published by Pro- 

 fessor Fabre in 1855, and represents the web of 

 GeajjJuh'* convolvens, of which centipede Fabre 

 kept a number of individuals of both sexes for 

 some time in captivity. 



At the end of September this naturalist noticed 

 in passages in the mould in which the creatures 

 lived very small nets, formed of cobwebby fila- 

 ments, irregularly crossed, and extending from 

 one wall to the other of the passages. Similar 

 nets were seen also above the mould, between 



tremity of the body. Numerous attempt> were 

 made to ascertain the normal fate of the spermato- 

 phore and the manner in which fertilisation 

 was effected, but without success, for the female:-, 

 being possibly immature, took no notice of the 

 webs. The observer was satisfied, however, that 

 with this animal there is. in the ordinaiy way. n 

 individual connection between the sexes : and lie 

 suggests that the female may deposit her eggs 

 round the spermatophore. causing it to burst : or. 

 more probably, he says, she may come to the web 

 before laying her eggs and take possession of the 

 sperrnatophore. 



Species of Geoph Hits are common in this country, 

 and possibly some reader of Science-Gossip has 

 observed their spinning habits. 



Fabre's memoir is in the ''Annales des Sciences 



Web of Centipede (M. 



sprigs of moss. Near the centre of each net was 

 suspended, free from contact with foreign bodies, 

 a white globule of the size of a small pin's-head, 

 and this the observer at first believed to be an 

 egg. Under the microscope, however, he saw the 

 globule burst, and recognised in it. to his great 

 surprise, a drop of sperm, with spermatozoa in 

 full activity. Several globules were examined 

 with the same result, and it was clear that they 

 were the spermatophores of the GeophUus, After 

 two or three days the globules first observed dis- 

 " appeared, having been dried up. or devoured per- 

 haps by mites ; but new nets were formed, each 

 with a spermatophore in the centre, and so on, 

 during a month and a half. Therefore, in spite of 

 rapid destruction, five or six were constantly to be 

 seen. These webs, regarded as a sort of nest on 

 which the male lays his product, were believed by 

 Fabre to be spun by the male, from accessory 

 genital glands, which open at the posterior ex- 



(1) Web, with spermatophore. of Geophilus co/irolceus, much 

 enlarged. After Fabre, " Annales des Sciences Xatnrelles "" : 

 Zool. (4), UL (18-55 ). pi. IX. fig. 23. 



Naturelles/' Zool. (4). III. (1855), pp. 257-316: 

 and one may refer, also, to Ryder, i; Proc. Acad. 

 Nat. Sci. Philadelphia^ 1881. pp. 79-86 : and 

 Zograf. •• Zoologischer Jahresbericht. r 1883. Abth. 

 2, pp. 88-92. 



II. The Slime-jets of Pebipatts. 



Peripatus. one learns, possesses paired slime- 

 glands with reservoirs, the contents of which it 

 can suddenly eject through openings at the tips of 

 a pair of oral papillae, in the form of fine jets of 

 tenacious fluid, which, hardening quickly, may 

 form M networks of fine threads, looking like a 

 spider's web : " ('-). 



Originally described as a mollusc, and for years 

 a st>rt of zoological shuttlecock. Pervpatus t as most 

 readers will remember, is one of the most remark- 

 able animals in the world. Though now definitely 

 recognised as belonging to the Arthropoda. among 

 which a separate class has been created for it, it 

 has undeniable affinity with higher worms, and is 

 even regarded as a sort of half-way animal between 



i.i Moseiev-. " Encyclopaedia Britannica," ed. 9, xviL (1*84). 

 pp. 11-5-117. 



