II OVIl'OSITION NURSING 55 



B. Amiilexus of leiigtliy duration ;uul in tlic water. 



'(. Tin- iiiak', distiiiguislied liy a greater develoimient of the fore- 

 limlis, whicli an- armed with teiii])orary excrescences, clasps tlie 

 female in the axillary region with the fore-limbs : Triton valfli. 

 h. Tlie male, distinguished liy a greater development of the hiiid- 

 liiiilis and a ]irehensile tail, clasps the female in the lumbar and 

 caudal regions : The E uprodus-^vouY of newts : Triton u.-iprr, 

 T. rusconii, ami 7'. vwnfanns. 



The act ul" fecuiidutiou of most of the other kinds of Urodela, 

 notably Crypfohr<inclniji, Amphiuma, Froteus, has not yet been 

 observed. 



Embracing of the two sexes is the universal rule with the 

 Anura, the male creeping on to the back of tlie female and 

 clasping her firmly with the arms and hands either in the 

 inguinal region, higher up, or under the armpits. See the 

 numerous statements in the systematic part. This often ex- 

 tremely forcible, pressing embrace seems to be necessary, although 

 the females can deposit the eggs without the help of the male, 

 but in such cases the expulsion takes place at irregular intervals 

 instead of at one time. When the eggs appear at last, and this 

 happens in many species many hours, or even some days, after 

 the beginning of the embrace, the male voids the contents of 

 its seminal vesicles over them. Fertilisation is consequently 

 external, with the possible exception of Fij)a, (j.r. ]>. 15 2. 



Deposition of the eggs and nursing habits. — The majority 

 of the Amphibia are oviparous, but some Apoda and Urodela 

 are viviparous. It is unnecessary to call the latter condition 

 ovo-viviparous, since this is really a distinction without a 

 difference. 



Viviparous forms : — amongst Urodela ; Salarnandra maculosa, 

 the young burst the egg-membrane in the act of being born, and 

 are provided with long gills ; S. afra, the young undergo their 

 whole development and metamorphosis within the uterus (see 

 p. 119): Spelerpes fasnis, the young are likewise born in the 

 perfect condition : amongst Apoda : Tijphhrnectes covipressicauda 

 and iJcr/nophis t/iomensis. 



T]iti oviparous Apoda, at least Ichthyuphis and Hypoijeo'phis, 

 and a few of the Urodela, as Desmognathns and Ainjyhiuma, take 

 care of their eggs by coiling themselves around them in a hole 

 midergroinid. 



Nursing habits are very common amongst the Anura. 



