164 M.Fabre on the Development of the Myriapoda. 



of the seminal canal {canal vecteur du sperme) ; their number is 

 small, as thei*e are us^^ally less than seven of them. They are 

 reniform ; their external envelope is very thick, transparent and 

 elastic ; the internal envelope, which is very fine and loose, pro- 

 trudes, in the form of a dull white nipple, through an orifice of 

 the first envelope. In water this nipple becomes inflated, pro- 

 jects more and more, and at last bursts and gives issue to bundles 

 of spermatozoids. 



In the Geophili " several of the spermatozoids are rolled to- 

 gether in a circular form, and superpose their diff'erent spiral 

 turns so as to form a ring, or rather a short hollow cylinder of 

 rolled cords. Each cylinder is then clothed with a protective 

 coat formed of hyaline particles, slightly agglutinated. At 

 the least contact this fugacious envelope breaks up into light 

 flakes." No one has yet succeeded in seeing the copulation of 

 the Chilopoda. M. Fabre has been no more fortunate in this 

 respect than his predecessors, but he has observed some exceed- 

 ingly curious facts which may explain the mode of fecundation 

 in these animals. He says: ''At the end of September, in 

 examining some specimens of Geophilus convolvens, Fabre, which 

 I had kept for some time in captivity, I observed in the passages 

 formed by these animals in the mould which served for their 

 abode, some very small nets, formed of arachnoid filaments, 

 arranged at a great distance apart. Their woof was composed of 

 a small number of threads stretched across from wall to wall of 

 the passage, and irregularly crossed. Other similar nets ap- 

 peared out of the mould, stretched between some stalks of moss 

 with which I had completed the filling of the bottle. At the 

 centre of each, far from contact with any solid body, was sus- 

 pended a white spherical globule, of the size of a pin's head, 

 which I took at first for an egg. Having detached one of these 

 nets, I examined the globule with the microscope : its delicate 

 envelope burst with the first contact. What was my astonish- 

 ment at recognizing in this globule a little drop of semen, with 

 its cylinders of spermatozoids in full gyration ! Several others 

 were collected, and the results were the same. Inexplicable as 

 this exceptional case was, doubt was impossible : I had certainly 

 the semen of the Geophilus before me. In two or three days 

 these first globules had disappeared, either drying, or being de- 

 stroyed by Acari, which appeared to be very fond of them. But 

 new nets were already spread with their drop in the centre, and 

 this continued for about six weeks ; so that notwithstanding their 

 rapid destruction, there were always five or six of them in the 

 bottle. I observed the last on the 12th of November." 



The Geophili, and probably also the other Chilopoda, conse- 

 quently deposit their spermatophora upon an arachnoid net- 



