March lo, 1881 J 



NA TURE 



447 



animal. But all my efforts being unsuccessful for a long tijie, I 

 finally lost all hopes, and the pressure of other business, 

 scientific and not scientific, caused me to lay the matter on the 

 shelf, little thinking that I had my desideratum close at my 

 elbows. 



There is within our University building a large square yard, 

 where stones, old bricks, and other such refuse had been accumu- 

 lating in the course of years. About a month ago it was fortu- 

 nately resolved to transform this very ugly place into a garden, 

 and I engaged the workmen to bring me any kind of animal they 

 might turn up under the heaps of rubbi-h. How preat was ray 

 satisfaction to find in the very first gatherings half a dozen of 

 Perifatus among some common beetles, centipedes, and earth- 

 worms ! I offered immediately a prize for every other speci- 

 men of the former, and so good proved the locality that in a 

 few days I was in possession of more than fifty of these un- 

 expected cives acadcmici of ours, the supply being apparently 

 far from exhausted. ^ 



As there are still some points in the natural history of 

 Peripatiis which are not well settled, I beg leave to offer the 

 following remarks based on the careful examination of living 

 or dissected specimens. 



The number of females appears to be much larger than that 

 of males ; for among fifty-three specimens I found only five 

 males, which are about lialf the size of the females. These are 



Fig. I. Fig. 2. 



Fig. I. — Horny claws of one of the foot-j.iwj in the young animal wh.-n born- 

 FlG. 2. — The same, from an adult female, (z, first claw : //, second 

 claw ; c, horny saw ; d, pigment-line. 



sometimes nearly I decimetre long, 5 to 6 millimttres broad, 

 and somewhat tapering on both extremities. The colour is 

 brownish black, viith a diffused black line on the middle of the 

 back ; the ventral side is dark flesli-coloured. Full-grown 

 animals have thirty-one pairs of ambulatory feet, the new-born 

 animals have but twenty-nine; the length of the latter is about 

 25 millimetres, their breadth t«o, the tentacles measure 3 mm. ; 

 their colour is reddish, with a line of somewhat lozenge-shaped 

 figures of a paler tint running down the middle of the back. 



I twice observed the birth of a young Pcripaitis. The mother 

 raised slightly the hind part of the body, moving it slowly from 

 one side to the other. After some minutes the head of the 

 embryo protruded from the sexual porus, and in half an hour 

 half the body came out, twisting around all the while in every 

 direction. The old animal remained rather quiet, moving 

 occasionally its head, but not crawling about. As soon as the 

 proce-.s was advanced thus far, the young Perifatus clung with its 

 feet to the nearest surface in its reach ; and the mother walking 

 off, the hind part of the embryo came forth in a few seconds. 



In one case a young Peri/>ai!is\\':i.i born in a tu..,bler of water, 

 in which I had placed the mother, in order to kill it in an ex- 

 tended condition, as recommended by_Mo.-eley in his well-known 

 paper in the PAH. Transactions. I did not see the birth, but 

 found the young animal already crawling on the back of the 

 mother, and there floated in the w ater close by a very thin skin of 



' Th jSe desirous of obtaining specimens from me in exchange for books 

 or papers on zojlogical topics, will be good enjngh to write to me. 



the size of the young aniiual, exhibiting its whole form, even the 

 tentacles. I suppose it must have been shed soon after birth, but 

 have failed hitherto to see anything alike in the other cases of 

 birtli, which I watched ver)' carefully. 



I could not well make out the number of articulations in the 

 tentacles ; there are, however, more than thirty in those of the 

 young animal, having each a ring of short spiny bristles at the 

 base. The slime-glands of the young Peripatiis are already well 

 developed. It lias twenty-nine pairs of feet ; and as the adult 

 animal has never more than thirty-one, there must be specimens 

 with the intermediate number of thirty, which would settle Mr. 

 Moseley's question {Ann. and Mag. of Nat. Hist., 1. c.) It is 

 probable that Peripatiis goes through several moultings, and 

 that the new feet then make their appearance. 



This may be further surmised from the development at the 

 horny claws of the foot-jaws, whicli are simple, and not indented 

 m the young animal, but of a much more complicate structiure 



Fig. 3. — Schematic sketch of ovary («), beginning of oviducts (^), caeca (c), 

 receptacula seminis (rf). covered by tracheal tubes (f), zjne of ovary 

 without tracheal tubes (/). 



in the old one. The annexed figures represent these claws in 

 both conditions. 



In the adult animal there is first a large pointed tooth, then 

 follows a shorter one, which is obtuse ; both are formed appa- 

 rently of three to four superposed lamells;, the outlines of which 

 are distinctly visible by changing the focus of the microscope. 

 The second maxillary claw has likewise two teeth of the same 

 shape and structure, but bears behind them a kind of saw, com- 

 posed of ten small teeth of the same amber-yellow colour as the 

 inner parts of the larger teeth. This saw is followed by an 

 oblique line of a yellowish pigment, perhaps the rudiment of 

 another developing saw, or a reservoir of horny matter. 



The structure of the sexual organs may deserve a few remarks. 

 There can be no doubt that the sexes are separate. The male 

 organs are very much like those described by Moseley in his 

 paper ; only the vesiculic seininales are not nearly s spirally 

 •■wisted as in his figure on plate lx.\ii. The testes contain Jsper- 

 matozoa of the same shape as those of P. Capeiisis, I noticed 



