228 BOTANICAL GAZETTE [OCTOBER 
GuYER*-draws the following conclusions from his own well known experi- 
ments with white rabbits, and from the results of other investigations. Basic- 
* : : : : 
op 
fundamental constituents under differing conditions of environment. There is 
evidently some degree of constitutional identity, probably protein homology, 
between the nature substance of a tissue and its correlative in the germ. 
Changes which can affect certain constituents of tissue cells initiate an influence 
which, borne in the circulating fluids of the body, evidently is able to affect 
the homologous constituents of the germ cells. This, of course, furnishes the 
basis for a Lamarckian view. The author feels that here may be a basis for 
progressive evolution.—M. C. Coulter. 
Influence of host on parasite.—Continuing his studies on the physiology of 
parasitism, Brown” has investigated the exosmose of substances from leaf and 
Lilium, Papaver, Iris, Petunia, Tulipa, Rosa, Begonia, Viola, Lathyrus (sweet 
pea), Dahlia, Geranium, Cydonia, Pyrus, and on leaves of several plants, includ- 
ing the broad bean. The change in the drops due to exosmose was determine 
by studying their capacity for germinating spores added to the drops in water 
suspensions, and also by electrical conductivity tests. Capacity for germinating 
spores was based on the average length of the germ tubes. An increase in 
conductivity resulted in all cases, accompanied in ie ie number of plants 
studied by increased germination capacity, when the drops subjected to exos- 
mose were compared with drops of distilled water of similar size. Petals diffi- 
cult to wet gave lower conductivity and germination figures. In some plants, 
with leaves of Tradescantia discolor, for instance, increased conductivity was 
accompanied by germination capacity only equal to or less than that of dis- 
tilled water, or by actual inhibition of germination. The exact source and 
nature of the inhibiting substance were not determined. 
Attention is directed to the difference in the behavior of fungal parasites. 
Some, like the rust fungi, penetrate both susceptible and immune varieties of 
plants, their ae thereafter being determined by internal conditions. Con- 
trasted with this is the behavior of Botrytis spores on the leaf of the broad bean, 
typical of another category of fungal parasites, in which the germination and 
attack depend upon the exosmose of substances into cag infection drop, which 
can be used as a nutrient by the fungus.—J. G. B 
% Guyer, M. F., Serological reactions as a probable cause of variation. Amer. 
Nat. 56:80-96. 1922. 
29 BROWN, WILLIAM, Studies in the physiology of parasitism. Ann. Botany 36: 101- 
119. 1922. 
