
7891.] The Vermilion-Spotted Newt. 1089 
fertilization and Ovulation—lIt has been assumed by most 
observers that, in analogy with the European tritons, the eggs of 
Diemyctylus are internally fertilized (Baird, ’51; Whitman, ’85), 
It is said to be external by Col. Pike (’86), who supposed that the 
eggs were laid in masses. So far as I have been able to ascer- 
tain, no one has previously undertaken experiments to definitely 
settle this point. The mode of copulation, if it may be so called, 
is so different from that described for the European tritons in 
which internal fertilization has been demonstrated that from it 
alone one would not expect internal fertilization. The hind legs 
of the male are exceedingly strong, and have developed on the 
ends of the toes dark, horny masses, also horny ridges along the 
inner or opposed surfaces of the legs (Pl. XXIII., Fig. 9). These 
are mostly absent in the summer. As the animals slowly 
move about in the water, when the male comes sufficiently 
near a gravid female, there is a rapid movement of the body to 
get above her, then the two powerful legs come together like the 
jaws of a steel trap, grasping the female either just in front or 
just behind her front legs. The ventral side of the male is thus 
applied to the dorsal side of the female in the thoracic region, and 
consequently the cloacal openings are very widely separated. The 
male keeps his position for an hour or longer, and during part of 
this time, as Baird (’51) remarks, “jerks the female round in the 
water most unmercifully.” The cloaca of the male is very widely 
open and pressed against the back of the female, and when not 
swimming around the tail is waved from side to side. The 
cloacal papilla or villi are brought into view by the eversion of 
the cloaca. They remind one of the cloacal villi or of the gill 
filaments of a male Necturus. In case the female shakes the 
male off, as sometimes happens, the cloaca of the male may 
remain everted, and the tail is waved from side to side while rest- 
ing on the bottom or on a branch of vegetation. This also 
occurs when he voluntarily leaves her for the purpose of deposit- 
ing spermatophores (Zeller, ’90; Jordan, ’91). 
As the egg-laying never takes place during the mating, the eggs 
must be fertilized after laying by the zoosperms diffused in the 
water, or the zoosperms must in some way get into the cloaca or 
Am. —Dec.—4. oy 

