288 



AMERICAN TESTUDINATA. 



Part IL 



the spermaries anrl ovaries are situated insi'le of it. Tlie speniiarics are oval, 

 and surrounded by a convolution of seminiferous canals, the hunen of which is 

 large, whilst their walls are t)fteu provided with a large amovuit of l)lack pigment^ 

 The spermatic ducts open into the cloaca on the top of a papilla near the open- 

 ing of the urinary organs. The penis is single, large, and retracted into the 

 cloaca, as in Crocodiles, while in Snakes and Lizards it is doul)le, and lies outside 

 of the cloaca.^ The form of the penis, particularly its end, exhil)its great diversity 

 in different families, the extremity Ijeing shuple in Testudo and Emys, for instance, 

 while it is branching in Trionyx. Tlie ovaries are very much as in Birds. The 

 number of eggs vfliich are matured in one year is, os in Birds, very different 

 in different families, genera, anil species. The eggs of the ovaries are largely 

 provided Avith bloodvessels. The oviducts begin with a tender but large tuba, 

 often provided Avith beautifully folded margins. In relation to the reception of 

 the eggs through these tulia;, Are liave couie, by numerous ol )servations, to the 

 strange result, that eggs from the left OA^ary are often received in the right tuba, 

 and vice A^ersa. Tliis fact is clearlj^ deuionstralile. We haA'e obserA^ed, in a 

 large nmnlier of cases, that tliere Avere more corpora lutea to be foimd in the 

 ovary of one side than eggs in the oviduct of the same side ; and the eggs Avhich 

 were Avajiting in this oviduct Avei'e found in that of the other side, 0)i Avldcli there 

 accordingly appeared fewer corpora lutea than tliere Avere eggs in the oviduct. 

 Whether this occurs only among Turtles, or, as Ave Avould rather believe, also in 

 otlier Vertebrata, we do not j'et knoAV. During their passage through the oviduct, 

 the eggs are provided AA'ith a thick, lianl, calcareous shell, as in Crocodiles, Avlule 

 in all other Reptiles we hnd onl}^ a leathery sliell. In connection AA'itli this. 

 Lizards and Snakes have, Avliile hatcliing, a sliarp tooth, to cut through tlie shell, 

 as Avith a knife.^ In Turtles, Ave find only a hard tiibercle upon the snout, by 



* We do not find ripe semen in the seminiferous 

 ducts of the young Emys picta (of which we had a 

 large series from the first year upwards) before it 

 has attained the seventli )'ear of its age. 



^ Stannius lias established a primary division, 

 among the Reptiles, upon this difference, and tliat 

 other peculiarity of a free movable suspeusorium 

 for the lower jaw in Saurians and Ophidians, which, 

 on the contrary, is immovable, and soldered by 

 sutures to the skull, in Crocodiles and Turtles ; 

 Ilandbuch der Zootomie, Amphibien, Berlin, lS.5fi, 

 p. 5 and 7. He there calls the Reptiles, Amphibia 

 monopnoa ; while the two large sections, founded upon 

 the characters mentioied above, are his Strepto- 



stylica, embracing the Ophidians and Saurians, and 

 his Monimostj'lica, the Crc)Oodiles and the Turtles. 

 Though we acknowledge a nearer relation between 

 Snakes and Lizards, and a greater difference be- 

 tween Saurians and Crocodiles, than is generally 

 admitted, we cannot see, on the other Iiand, a real 

 relationship between Turtles and Crocodiles. There 

 is, at least, no more affinity between tliem than 

 betweeu Saurians and Turtles ; and, tliough a group 

 comprehending Turtles and Crocodiles may be con- 

 venient in an anatomical point of view, it seems 

 to us at tlie same time artificial. 



' Tliis tooth was discovered by Johannes Miiller, 

 (see his Archiv fiir Anatomic und Pliysiologie for 



