4 o6 THE ANIMAL KINGDOM. 



Malpighian body. In other Amphibia the testes are compact bodies. The 

 Urodela have an internal collecting tube for the seminal tubes, which is 

 wanting in Anura, where there is generally an intratesticular network of 

 vessels. The collecting tube of Urodela is connected by a variable number 

 of transverse canals to a longitudinal canal (supra), and this in its turn by 

 other transverse vessels to the Malpighian bodies of the sexual region of 

 the mesonephros. The longitudinal canal is sometimes absent (Spelerpes) 

 and a direct connection then occurs between testis and kidney. The lon- 

 gitudinal canal is present in many Anura, but in Bufo only do the trans- 

 verse canals become connected with Malpighian bodies. For Rana, see 

 p. 78. In Bombinator most of the transverse vessels end blindly, and the 

 anterior are connected directly to the Wolffian duct. In Discoglossus a few 

 vessels connect the testis to the same duct, but in Alytes obstetricans the 

 extra-testicular network is connected to the Miillerian duct, which ends 

 blindly anteriorly, and opens posteriorly into the Wolffian duct. The Miil- 

 lerian duct always exists in the male. In Gymnophiona it may retain its 

 abdominal opening ; it is extremely glandular posteriorly, as in Bufo, and 

 each duct opens into the cloaca separately. In Bufo the two ducts unite 

 first and then open into the cloaca. It always loses in Urodela its cloacal 

 connection ; it sometimes preserves, sometimes loses, both its abdominal 

 opening and its cavity. In Anura, except Bufo, it is reduced to a solid 

 cellular cord. Some male Toads, e. g. Bufo cinereus, have a rudimentary 

 ovary. The ovary in Gymnophiona is a long thin band ; in Urodela a 

 cylindrical sac, and in Anura a sac subdivided by complete partitions into 

 a series of more or fewer compartments. The ova are shed into the coelome, 

 whence they are taken up by the abdominal apertures of the Mullerian 

 ducts, which are close to the anterior ends of the kidneys in Gymnophiona, 

 at the roots of the lungs in other Amphibia. They are straight in Gymno- 

 phiona, somewhat convoluted in Urodela, and especially so in Anura at the 

 breeding season. In viviparous Salamanders their distal portion is dilated 

 and functions as uterus. It fs also dilated and acts as a reservoir for the 

 albumen-coated ova in Anura. The two ducts open separately on the 

 dorsal wall of the cloaca, except in Alytes and Bufo, where they unite and 

 open by a common aperture. In both male and female Toads (Bufo) an 

 undeveloped and cellular remnant of the genital rudiment lies at the 

 anterior end of the sexual glands, and is known as Bidder's organ 1 . ' Fat 

 bodies ' of unknown function are found in all Amphibia, laterally placed to 

 the sexual glands in Gymnophiona : between them in Urodela and at their 

 anterior ends in Anura. The cloaca is partially eversible in the male 



1 For an account of this remarkable organ, see Knappe, M. J. xi. 1886. It tends to disappear 

 in the female sooner or later. Its cells closely resemble ova and are inclosed by follicle cells, but 

 isolated cells here and there have been observed to form spermatozoa. It occurs in hermaphrodite 

 individuals. 



