532 Adaptive Range of the Batrachians, &c. [Septembei, 
series of the most various combinations have been traced 
which may occur in these species. Sometimes the intes- 
tines, the lungs, or the gills, or only the general form of the 
body or the skin retains the transitory ontogenetic cha- 
racter. . 
Further investigations must show in how far the law ot 
correlation can be set aside, for in this respeCt also the 
Batrachians promise to be of a prominent importance. 
In connection with the above-mentioned faCts it must be 
discussed what organs in the Batrachians have the strongest 
influence upon correlation. We might d priori feel disposed 
to assume that the sexual organs, as determining the perpe- 
tuance of the species, would play the most important part. 
This, however, at least as far as the Urodela are concerned, 
is by no means the case. Their sexual glands come to ma- 
turity, the semen is evacuated, the ova are fertilised, so that 
new generations appear, — e.g., in the axolotl, and still the 
entire body retains its youthful formation. The sexual 
organs do not seem so intimately connected with the indivi- 
dual life of the animal that their development involves cor- 
relative phenomena in the remaining organs. 
With the organs of respiration the case is quite different. 
Not the development of the lungs per se, but their full phy- 
siological function, involves the most far-reaching changes in 
the entire organism. The hybernating Anoura, in spite of 
their fish form and their branchial respiration, have lungs 
which contain air ; they, therefore, doubtless inhale air from 
time to time. But these lungs are but small, and do not 
suffice for respiration ; their reduced form is not capable of 
exerting a profound influence upon the remaining organs. 
The skull, the vertebrae, and the intestinal canal remain in 
an embryonic condition, corresponding to the gills which 
perform the physiological duty of respiratory organs. The 
entire body, muscles and bones, and the ciiculation remain 
on the same ontogenetic stage of development as the gills 
that is, they remain embryonic. All this is changed at once 
as soon as the lungs come fully into play. In this respeCt 
the above-mentioned experiments of Miss von Chauvin are 
so exceedingly instructive, because they show most clearly 
how profound is the influence of the respiratory organs 
upon the correlative transformation of other parts of the 
organism. 
