1903.] TRANSPOSITION OF MAMMALIAN TESTES. 329 
is well known, they are “huge, heavy, clumsy creatures, with 
bent legs so short that the belly seems almost to drag on the 
ground.” The Subungulata comprise the Hyracoidea and the 
Proboscidea. The ancestry of the members of both these sub- 
orders is as yet undecided, their status, decidedly low in the scale, 
being obscure. The Hyracoidea are animals of about the size of a 
rabbit or somewhat larger, and “resemble small marmots.” They 
possess a “short, fat body” with “weak and short feet.” “In 
most species there is a complete adaptation to a life among the 
rocks,” by possession of curious clinging habits resembling those of 
the Geckos. They are “agile in their sports, but rather lazy where 
food is abundant.” Owen states that ‘‘the testes are abdominal, 
below or beyond the kidneys.” The low status of the Proboscidea 
is shown by several anatomical traits, such e. g.as the possession of 
two ven cave and the structure of the hmbs. These animals 
have been well described as “ peaceable colossi.” Their gait 1s 
“ pretty slow, though the Colossus can run very fast w ee once 
in full career, but this pace never lasts very lung and is always 
maintained in a straight lime.” Owing to their huge size 
Elephants never gallop. The most active members are the 
“rejected males ”— “such extra activity thus beimg neutral so far 
as the inheritance of any tendency to testis descent is concerned. 
Elephants are vegetable feeders and are “ gregarious, generally 
inoffensive and even timid, fond of shade and solitude and the 
neighbourhood of water.” The testes are permanently abdominal 
—a fact explicable by habits, though phylogeny alone can afford 
a complete solution. Here, as possibly also in the case of the 
Nasicornia, it may be pointed out that the huge size of these 
animals itself implies inactive ancestors, for, according to one of 
the conditions of growth enumerated by Spencer, great activity is 
antagonistic to Increase by bulk, and the occurrence of the latter 
negatives the past existence of the former. 
The order Carnivora is subdivided into the Fissipedia and the 
Pinnipedia. The members of the former group are all exceedingly 
active animals of large size,and, together with the Ungulata, include 
the swiftest of terrestrial siimals: Their testes, needless to say, 
reside in a well-defined scrotum. The Pinnipedia afford an inter- 
esting illustration of the secondary operation of natural selection. 
In the Otariide the “‘ hind feet are turned forwards under the body, 
and aid in supporting and moving the trunk as in ordinary 
mammals...... They spend more time on shore, and range 
inland to a greater distance than the true seals.” In the Otariide 
the testes are “suspended in a distinct external scrotum”?. On 
the other hand, in the Phocide, ‘the hind limbs are directed so 
far backwards that they continue the horizontal direction of the 
vertebral column ...... They move on land only with difficulty 
by fixing themselves with their flippers in front and pulling up 
their hinder parts, then drawing their bodies up into a curve and 
1 Owen states that the scrotum is not distinct. 
