Miscellaneous. 245 



axilla and complete the circuit. The pair are thus firmly united ; 

 and the dark colour common to the two sexes aiding the confusion, 

 it is even necessary to look very closely at them in order to recog- 

 nize the real position of the parts, and distinguish what belongs to 

 each of the animals. The male swims to and fro carrying the 

 female with him, the latter appearing inert and making no move- 

 ment ; from time to time he sinks to the bottom, detaches one of 

 his feet, the right one in the tolerably numerous observations that 

 we have made, and turns round upon the left limb, which he con- 

 tinues to hold grasped by his own. In this manoeuvre he stretches 

 himself out at first in front of the female, with the extremities of 

 the two muzzles nearly against one another ; then he continues his 

 evolutions so as to place himself parallel to her left side. His tail, 

 at this time, performs rapid undidations, a sort of shivering which 

 resembles the analogous movements described by llusconi in Triton 

 cristatus. From time to time he endeavours to turn himself over 

 beneath the female in order to bring his cloaeal aperture near to 

 hers. In all probability it is thus that the actual copulation is 

 effected; but hitherto we have not been able to ascertain this posi- 

 tively. At the end of a variable time the male resumes his first 

 situation beneath the female* and begins to swim again ; and it is 

 not until after having several times repeated this process that the 

 animals finally separate. 



At the period when these facts were observed for the first time 

 they were not followed by any result ; but this year, towards the 

 middle of February, the Pleurodelce copulated again ; and on the 

 25th of that month oviposition commenced, and continued during 

 at least two months and a half. It was, however, particularly 

 abundant at first, when the ova could be collected by hundreds. 



These ova, which are not unlike those of the Axolotls, are at- 

 tached to submerged bodies, especially to stones, and isolated from 

 each other (that is to say, without any actual connexion) when, as 

 is frequently the case, they are close together. The transparent 

 albuminous sphere measures from 7 to 10 millims. in diameter, the 

 egg, properly so called, being not more than 2 millims. The latter 

 at first is black in its upper hemisphere, except a central polar point, 

 of which the colour is yellowish, like that of the inferior hemi- 

 sphere ; at the end of three or four days it becomes entirely of a 

 yellow colour, and one can distinguish the mark produced by the 

 evolution of the primitive streak. 



It seems useless to dwell upon the evolution, which presents 

 nothing peculiar. The eggs being placed in the best condition of 

 heat and light, the young issued from them from the 16th to the 

 20th day after deposition. The adherent hooks disappeared on the 

 thirteenth day after exclusion, at which period the young tadpoles 

 possess a tridactyle arm ; eleven days later the posterior limbs are 

 already somewhat developed. Finally, the animals at about two 

 months and a half measure 0'07-0 - 08 metre, the branchiae are 

 atrophied, and, except in size, they have acquired the characters of 

 the adult. 



