Eimer on Growth and Inheritance 439 



they both assume is avowedly antagonistic thereto. Truly 

 we may urge on the attention of both these naturalists the 

 Tubingen Professor's own words : ^ ' If we philosophise about 

 nature at all, the naturalist who desires to he thorough must 

 not halt half way.' 



\ In his fourth chapter our author applies himself to the 

 main question — that of the transmission of characters 

 acquired by parents. Very curious effects on organisms may 

 sometimes be produced, which cannot be considered as re- 

 sulting from any inherited capacity, since structures are 

 developed which the parent organisms never possessed. The 

 following ^ is one example : — 



' Very pretty experiments ^in relation to this point have been 

 made by Fraulein Von - Chauvin upon the Alpine salamander, Sala- 

 mandra atra. The gill-bearing larvae of this animal were taken out 

 of the oviduct of the mother and put into water. It is well known 

 that these larvae under the usual conditions at a later time, while still 

 within the mother's body, lose their gills, and, what is very rare 

 among amphibians, are born as completely terrestrial animals. The 

 gills of the larvae placed in water at so early an age were dispro- 

 portionately large and hindered the animals in their movements, and 

 in some cases they were cast off, whereupon new smaller organs arose 

 in their place. These new gills persisted in one case for a surprisingly 

 long time (fourteen weeks), and then atrophied. This larva, like the 

 rest, ultimately developed into a land animal. But the remarkable 

 fact remains that on account of the peculiar conditions of life artifi- 

 cially produced, after the original gills, which were unadapted for use 

 in a free state of life, had perished, new and suitable gills were 

 formed, not in the struggle for existence against competitors with the 

 cumulative effect of selection, but, as I believe, directly from purely 

 physiological causes.' 



As to acquired characters which are due to direct ex- 

 ternal action, he brings forward many interesting examples 

 concerning the relation of colour in organisms to the light to 

 which they may be exposed. The green colour of plants 

 P. 70. P. 81. 



