1868. | Zoology. 123 
sistence of the gills is purely accidental: they are of no functional 
importance, and may be cut off without injuring the animal. When 
cut, they grow again, and may be again cut. Persistence in cutting 
the gills causes the Axolotl at length to undergo certain changes in 
colour and appearance, and to approach more closely to the fully- 
developed Salamandroid. It is a remarkable thing that even whilst 
these gills, evidently the mere relics of larval structure, are attached 
to the Axolotl, it becomes sexually mature, and breeds (as it has 
done at Paris). M. Duméril appears to show that sometimes an 
Axolotl may lose its gills at an early period of life—in other cases, 
perhaps not at all—and there is great variability in the time when 
the supply of blood to these parts is cut off, and an absorptive process 
commenced. Perhaps the diminution of accessible nutriment might 
have some effect in causing an earlier absorption of the appendages. 
The most important of M. Duméril’s observations—zoologically— 
is the discovery that the Axolotl does spontaneously lose its gill- 
tufts and tail crest, and becomes a true Salamandroid—approaching 
certain North American forms. In fact, M. Duméril says the Axolotls 
are only the tadpoles of the Amblystomi, and, most strange to say, 
have the power of sexual reproduction as tadpoles. Does not this 
open up a case for the students of natural selection? The tadpole 
of a northerly Batrachian, when placed in a tropical clime, tends to 
retain its tadpole form, and to acquire sexual maturity in that con- 
dition (or vice versi). But there are almost the same remarkable 
facts with regard to our own common newt. 
Amphioxus and Nerve Termination—M. P. Bert has some 
remarks on this lowest of vertebrates in the ‘Comptes Rendus.’ It 
has been taken this year for the first time on the oceanic shores of 
France, though many specimens have been observed on the Eng- 
lish south coast. M. Bert corrects some of the errors made by M. 
de Quatrefages. He denies the existence of the lateral canal open- 
ing at the side of the mouth, and describes the position of the 
abdominal pore and its relation to the body cavity. Like all other 
fish, Amphioxus has the generative glands early developed, and it 
has been strangely asserted by Agassiz that it is an immature form. 
M. Bert has seen it spontaneously discharge the spermatic fluid, 
which proves the assertion to be baseless. He also speaks of the 
termination of the nerves in corpuscular bodies. This gives us an 
opportunity to refer to a paper on the same termination of nerves 
in various animals published n M. Robin’s Journal. In these, also, 
corpuscular terminations are described closely connected with muscle 
fibres. M. Bert very properly maintains that in Amphioxus there 
is a retiform or endless disposition of the finer nerve twigs as well 
as these corpuscles. No doubt the reconciliation between the views 
of Dr. Beale and of his opponents (who are now becoming very few 
in number) will be found in admitting fully both methods of ter- 
