in PHYSIOLOGICAL VARIATION IN SEEDS 137 



stance, in one case I have had animals of four or five 

 millimetres in length only, while some of their brethren 

 were over ten millimetres long, at the same age. In 

 another case the difference between lengths was from 

 three to ten, and in width from two to six. More 

 detailed facts concerning this point I intend to publish 

 shortly in a special paper, and I shall try to establish 

 a comparison especially between the different indi- 

 viduals of the same brood parthenogenetically pro- 

 duced, or at least produced without previous fecunda- 

 tion by a different animal of the same species, for it is 

 a positive fact that Lymncea stagnalis and auricularia 

 can yield fertile eggs without fertilisation by another 

 individual having taken place. Similar facts are to 

 be noticed among plants, as every one knows. Cornevin 

 has provided a new demonstration of the fact by sub- 

 jecting seeds of the same plant to the same conditions. 

 He took thirty seeds from the same pea-plant, and 

 steeped them some thirty hours in a solution of 

 colchicin, and then planted them. Out of the thirty, 

 twenty-five were entirely killed, and out of the five 

 which survived, only three were able to develop a 

 normal plant. Some years ago I had noticed similar 

 facts, in a different manner. Four species of seeds 

 were subjected to the influence of heat in the following 

 manner : In one series the temperature was 80 Cent., 

 and the seeds remained two minutes in the heated 



