284 REPORT OF THE CONFERENCE ON GENETICS. 
Another point Dr. Tschermak speaks of is the intensification of 
characters. Hxamples were seen in his crossings of wheats and barleys 
in the length of the ear. This he attributes to the recombination of a 
number of existing characters that we cannot perceive. Other cases 
there are where there is no return of a pure parental form, and that is for 
us a great difficulty. We do not understand what is the meaning of the 
crosses; we are not quite certain, at all events, of the cases where no 
return is made to the pure parental form. Mr. Hurst tells us for example 
that, from a crimson zonal pelargonium in the first generation, in the 
second generation he has got almost all the colours that occur in zonals 
with the exception of the crimson he put in to begin with. We have 
seen the same thing in fowls. I think Professor Tschermak suggests 
that that may be due to recombinations, or that dominant characters 
have been present, which hide the parental type and prevent it from 
reappearing. 
These things show us, with regard to evolutionary conceptions, first, 
that we must be very careful in using results of crossing as an indication 
of history, because new forms that appear may either have occurred in 
the past history, or they may be novelties. 
Professor Wittmack said that Dr. Tschermak crossed winter rye with 
summer rye, with the result of showing that the winter forms became 
much more winter forms, and the summer forms much more summer 
forms, thus showing that outer influences had a great effect on the length 
of the vegetation; that outer circumstances can have influence. There- 
fore the changing of Mendel’s numbers altered the ratios. 
The President: This is a most interesting line of inquiry as to 
whether the ratios can be altered by external progressive influence 
generation after generation. I think any evidence of a definite kind 
bearing on that particular part of the problem will be of great value 
to us. 
Mr. R. A. Rolfe: As to the self-fertilisation of hybrids I think it is 
due to the fact that the pollen aggregates together in the mass, and 
insects cannot carry it away. I have got a good number of the second 
generation of hybrids self-fertilised. I am in hopes that in the second- 
generation-hybrid-flowers we shall get some rare and interesting evidence 
as to the way in which these characters work out. Variability seems 
to be increased by crossing ; but however hard you may try to get all 
the qualities of both parents combined, as a general rule you cannot do it. 
You cannot always do as you like. What I have noticed is that when 
you take two forms that are very much alike—near relations—the 
variability is slight; but when you take two diverse forms of different 
descent, then the variability is very great. 
The President: I must express the thanks of the Conference to 
Professor T'schermak, and I hope that in future he will be able to carry on 
his intensely interesting and valuable work under better conditions. 
