328 MR. W. WCODLAND ON THE [Apr. 2], 
hand to the jumping-shrews among the Insectivora.” These 
animals, unlike the Macropodide, move their hind limbs alter- 
nately in the process of walking. Unfortunately the writer has 
been unable to discover detailed information with regard to the 
testes in these groups. Other families are the clumsy, thick-set 
Hystricide, the very active Castoride (Beavers), Myoxide (Dor- 
mice), and Muride. During the rutting-season the testes of 
Rodents migrate more posteriorly than at normal times; but this 
merely indicates a slight displacement probably due to the periodic 
enlargement of the organ, the cremaster muscle effecting return 
by decreasing the capacity of the scrotal emergence. This can be 
well seen in the Muride, where the slightest impact will cause a 
dislodgment of the testis. 
The order Insectivora comprises ‘‘small animals ...... of very 
low type...... belonging to the oldest mammalian stocks...... 
which are generally terrestrial, although rarely of arboreal or aquatic 
LDVOMS 5 bo bec the greater number are cursorial.” “ In the sub- 
family Centetine, and Chrysochloris, the testes lie immediately 
behind the kidneys, but in others more or less within the pelvis; 
during the rutting-season they become greatly enlarged, forming 
protrusions in the inguinal region.” The various families of this 
group afford good illustrations of the correlation of impulsiveness 
with degree of testis transposition. As stated above, in the 
Centetince or ‘‘ Crawlers ”—the appellation denoting their mode of 
locomotion—and Chrysockloris, which is active and fossorial, 
the testes lie just posterior to the kidneys, 7. e. are abdominal. 
In the companion subfamily, the Oryzorictine, the two genera 
are represented by small animals—Macrogale being mouse-like 
with a long tail, and Oryzorictes mole-like in form. The testes 
are situated near the urethra. In the Hrimacemme or Hedgehogs 
the testes are situated on the “‘ underside of the inguinal canal.” 
Their ‘‘ movements are sluggish, their steps almost tottering, their 
gait clumsy.” On the other hand, in the active Soricide (Shrews) 
and saltatorial Macroscelide (Jumping-Shrews), the testes project 
at the periphery of the perineum, and in the Solenodontide, the 
feet of which are ‘‘formed for running,” the “testes are received 
into perineal pouches.” 
In the order Chiroptera, the members of which are so highly 
specialised for flight, there is “no scrotum, and the testes are 
either abdominal or inguinal. ” “ We find in the low organization 
of their brain a proof of their inferior status ”—a fact otherwise 
implied by the absence of the scrotum, unless a secondary reten- 
tion has occurred owing to the danger of partial externality 
involved in the conditions of flight and position of the hind limbs. 
The order Ungulata is subdivided into the Ungulata vera and 
the Subungulata, In the former suborder, needless to say, the 
testes of the large majority reside in a well- ‘defined scrotum, cor- 
responding to the eminent impulsiveness of the animals. In the 
Nasicornia (Rhinoceroses), however, ce testes are inguinal, the 
tunica vaginalis communicating freely with the body-cavity. As 
