Phenomena and Problems of Self-Sterility. 261 
IV. —Inheritance of Self-Sterility. 
Breeding experiments have however been performed in two 
cases of self-sterility; though in neither instance have the results 
so far been published in full. Baur (1911, p. 212) working with 
Antirrhinum-majus (self-fertile) and A . nolle (self-sterile) finds that the 
F t hybrid is self-fertile, and that P 2 consists of a majority of self- 
fertile and a minority of self-sterile plants: exact countings not 
having been made. Compton (1913) has published a preliminary 
note on his experiments with Reseda odorata, a species in which 
certain individuals are self-fertile, others self-sterile. The work is 
incomplete, but seems to show that self-fertility behaves as a 
simple Mendelian dominant to self-sterility. 1 In these cases the 
simplest explanation appears to be that self-sterility is due to the 
absence of some substance either nutritive or stimulating to the 
growth of the pollen-tube. On the assumption that self-sterility is 
due to the formation of an anti-body, self-fertility would result from 
the presence of a substance which inhibits the action of the anti¬ 
body (as do the anti-immune-bodies and anti-complements of Ehrlich 
in the case of immunity). 
Spermatozoa are known, from the experiments of Landsteiner, 
Metchnikoff and Moxter, to be able to call forth immunity against 
similar spermatozoa in the blood serum of an animal into which 
they are injected. Loeb considers that part of the effect of a 
spermatozoon in stimulating the development of an egg (namely 
the precipitation of the membrane) is due to the introduction of a 
lysin. It may be, therefore, that the acquired immunity of serum 
against spermatozoa is due to the development of antilysins. The 
individual and group differentiation in the haemolytic anti-bodies 
produced by different animals of the same species, as demonstrated 
by Ehrlich and Morgenroth, may be paralleled in the similar 
differentiation in cases of self-sterility: and it is suggested that the 
two sets of phenomena may have the same kind of explanation in 
terms of the specific neutralising reactions of organisms to hetero- 
or auto-intoxication. 
V.— Self-Sterility a Racial Character. 
The problem of self-sterility as understood until recently 
involved a problem of individuality. It was believed that a self- 
sterile plant is fertile when pollinated from any other plant of the 
1 Mention may also be made of the result obtained by East (1913), who 
found that on crossing Nicotiami alata grandiflora with N. forgetiana , both self- 
fertile species, the F, plants were completely self-sterile but fertile inter se. 
Further statements will be awaited with interest. 
