548 
One of the most interesting facts which lend support to 
this view of the backward development of the axolotl is 
the discovery that the axolotl has a rudimentary inter 
maxillary gland furnishing a glutinous secretion, and 
which serves to aid the capture of insect-prey. Now, as 
this gland exists in a perfect shape in all land amphibians, 
but is absent in gill-possessing forms, its presence in the 
gilled axolotls would seem to indicate that these animals 
retain the gland as a legacy from the higher or ambly- 
stoma stage, from which they are believed by Dr. Weismann 
to be descended and retrograded.* 
So far as my present argument is concerned, it is un 
necessary that we should determine which is the correct 
view with respect to the actual and existing axolotl. If it 
be a progressive stage, it represents a stage in the evolu 
tion of the race awaiting further development. If it be a 
retrogressive form, we are either deprived of any evidence 
whatever of the progressive evolution of the race, or we 
must accept the axolotl conditions as more or less repre 
senting a half-way house past which the amblystoma race 
must have travelled—back to which the amblystoma has 
reverted, with some characteristics inherited from its 
amblystoma parents. For the purposes of the present 
argument, either of the above suppositions may be enter 
tained. What we are specially concerned to know is 
whether we can find any trace whatever of the action of 
Natural Selection in this connection. 
Dr. Wilson, who believes that the axolotl is a larval 
form, refers the change to transforming influence. The 
case of the axolotl, he says, illustrates powerfully the 
effects of a change of surroundings in metamorphosing a 
species. A succession of dry seasons, operating in the 
Wilson, p. 248.