ON THE WYANDOTTE CAVE AND ITS FAUNA, 417 
which appear latest in embryonic history are lost, we have simple 
retardation, that is, the animal in successive generations fails to 
grow up to the highest point, falling farther and farther back, thus 
presenting an increasingly slower growth in this special respect. 
Where, as in the presence of eyes, we have a character early 
assumed in embryonic life, the retardation presents a somewhat 
different phase. Each successive generation, it is true, fails to 
tome up to the completeness of its’ predecessor at maturity, 
and thus exhibits “ retardation,” but this process of reduction of 
tate of growth is followed by its termination in the part, long 
before growth has ceased in other organs. This is an exagge- 
ration of retardation. Thus the eyes in the Orconectes probably 
onee exhibited at maturity the incomplete characters now found in 
the young, for a long time a retarded growth continuing to adult 
age before its termination was gradually withdrawn to earlier 
stages. Growth ceasing entirely, the phase of atrophy succeeded, 
the organ become stationary at an early, period of general growth, 
being removed, and its contents transferred to the use of other 
parts by the activity of “ growth force.” Thus for the loss of 
late assumed organs we have “ retardation,” but for that of early 
assumed ones, “ retardation and atrophy.” ; 
In comparing the list of animals from the Wyandotte with that 
of the Mammoth Cave, it will be observed that the representatives 
1n the former, of two of the blind genera of the latter, are furnished 
with eyes. These are the Hrebomaster and Spirostrephon, which 
correspond with the Acanthocheir and Scoterpes respectively. In 
the outer: part of a branch of the Wyandotte I took two eyed 
beetles the Quedius speleus and a Platynus. 
J out-door relatives of the blind forms are various. Those 
having congeners outside are the Spirostrephon, Campodea, Ma- 
chilis, Phora, Raphidophora. Those with near but few allies, the 
colerpes, Amblyopsis and thé three Gonyleptide. Species of the 
: 
te 
. 
a 
` œcidotea are marine. Those of the Caulozenus are partly 
marine, and those of the Stygobromus fresh water and marine. 
i The mutual relations of this cave life form an interesting sub- 
ig Th the first place, two of the beetles, the crickets, the cen- 
Pede, the small crustaceans (food of the blind fish) are more 
ER. NATURALIST, VOL. VI. 97 
