286 
R. Ruggles Gates. 
The parallel induction in germ and soma is believed to be brought 
about by “ altering the nature of the metabolic products included in 
the living protoplasm.” That such effects are transmitted for one 
or two generations is an excellent example of a cytoplasmic effect 
temporarily inherited, and indicates that minimal quantities of such 
substances are multiplied so as to produce a powerful effect. 
Kammerer claims to have obtained such a result in experiments 
with a lizard, where the character white instead of red belly, 
impressed by high temperature, was transmitted through the sperm 
to the next generation of adults. 
The experiments of Kammerer (1909, 1919) with Alytes 
obstetricans have been much discussed. His recent results are 
largely confirmatory of earlier papers published ten years ago, and 
a number of other contributions, including an elaborate series of 
experiments with salamanders, have appeared in the intervening 
years. It is well-known that Alytes differs from other European 
Anura in that its strings of eggs are not laid in the water. 1 but are 
twisted round the legs of the male and carried for some time during 
their stages of embryonic development. Their bearer only resorts 
to the water when they are ready to hatch as advanced tadpoles 
having a single pair of gills covered by an operculum. 
When these animals are kept at a higher temperature (25?— 
30° C.) with access to water, the eggs are laid in the water, and they 
hatch earlier, when the gills are still exposed. If these conditions 
are continued, so that the animals are obliged to breed in the water, 
by the F 4 generation the tadpoles will have three pairs of gills as 
in other frogs. A number of other interesting changes occur. 
The eggs of Alytes are much larger and less numerous than in other 
frogs and toads. Thus, Rana produces 600-4,000 eggs with a 
diameter of only 1*7 mm, while in Alytes the number of eggs is 
about 60 and they are 3*5-4 mm. in diameter owing to a great 
amount of yolk. Developing in the water, the eggs of Alytes 
become rapidly smaller in successive generations. 
But perhaps the most critical of these results concerns the 
secondary sexual characters of the male. Here again Alytes differs 
from other Anura in the absence of the characteristic horny pad which 
developes on the thumb or wrist of the male during the breeding 
season, enabling him to retain his hold on the female while in the 
water. When pairing and egg-laying occur in the water, however, 
according to Kammerer this pad gradually appears in Alytes, until 
1 It is an interesting fact that in one locality, Munster in Westphalia 
(Kammerer, 1909, p. 452), the eggs are normally laid in water. 
