208 



The Journal of Heredity 



gathered from plants fertilized at sunset 

 produced 92% of female plants. 



"In view of the success of these 

 experiments in fertilization I took up, 

 in 1877, six female plants with their 

 roots, before they had fully produced 

 their flowers, and transplanted them 

 into pots; as soon as the plants were 

 well rooted I transferred the pots to 

 the windows of two rooms looking south, 

 three pots in each room. Thereafter, 

 with a brush, I fertilized the three 

 plants in one room with pollen which I 

 collected from anthers just dehiscing 

 and not yet fully open (this pollen I 

 shall refer to as fresh), and the three 

 pots in the other room I also fertilized 

 by means of a brush, but with pollen 

 taken in the morning and kept in paper 

 till evening. The three plants fer- 

 tilized with 'fresh' pollen produced 120 

 seeds; the three fertilized with 'stale' 

 pollen produced 96 seeds. 



"In 1878 I sowed in my garden with 

 great care the seeds of the two lots 

 se])arately at distances of 20 centi- 

 meters. The 120 seeds derived from 

 fertilization with fresh pollen produced 

 112 plants, of which only six were 

 female, all the rest being male. But 

 the other 96 seeds, sprung from fer- 

 tilization by stale pollen, produced 89 



])lants, every one of which was female. 

 I have several times since repeated the 

 experiment, always with a similar 

 result." 



Having reached this result in plants, 

 Ciesielski extended his investigations to 

 animals, and tested his theory in 

 numerous experiments with rabbits, 

 dogs, horses, and cattle, an over- 

 whelmingly large number of which, he 

 states, served to verify his previous 

 results. Finally, Ciesielski declares 

 that he has repeatedly recorded the 

 application of the same law in man also. 



To sum up: According to Ciesielski 

 the sex of the progeny is governed by 

 the conditions of fecundation and the 

 law discovered by him applies to all 

 living lacings, whether plants, animals 

 or man. In dioecious plants fresh pollen 

 produces male seeds, while the effect of 

 stale pollen is the production of female 

 seeds. Similarly the sex in animals is 

 determined by the age of the sperma- 

 tozoa at the time they unite with the ova. 



In plants this discovery will be of 

 more or less academic interest, but in its 

 relation to animals and man the results 

 arc sure to be important and far- 

 reaching — if it endures the light of the 

 continued experimentation to which this 

 new "law" is already being subjected. 



Nature and Time of Segregation 



That segregation of unit characters may occur in somatic di\"isions is the con- 

 tention of William Bateson. Discussing the svibject before the seventeenth Inter- 

 national Congress of Medicine, he said: 



"First, as to the nature of segregation. This, I think, we must regard as a 

 process comparable with the mechanical separation of substances which will not 

 mix, or mix imperfectly; whereas some factors are continually transmitted in 

 their entirety, others are liable to be broken u]) by what I regard as a process of 

 quantitative fraction occurring in the mechanical dissociation of the elements at 

 certain critical cell divisions. As to which are the critical cell divisions, we have 

 no clear indication. I cannot agree with those of my colleagues who think segre- 

 gation must occur exclusively in the maturation ])rocesses. The case of the double 

 stock, in which the whole male side of the i)lant differs geneticalh' from the female 

 side, as proved by Miss Saunders, shows almost conclusively that segregation 

 may occur in somatic divisions. It is also difiicult otherwise to interi)ret the fact 

 that in certain cases the parental combination inHuences the distribution of factors 

 among the gametes so that the distribution among the grandchildren is different 

 according to the way in which the characters were combined in their grandparents." 



