72 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



A total of 1491 seeds were sown, and they produced 418 plants, 

 all of which were females. The relatively low percentage of 

 germination of seed in Merciirialis annua is present in all cultures 

 of males, females, and hermaphrodites and cross-pollinated seed. 

 The seeds upon ripening are often lost because of the sudden burst- 

 ing of the seed capsule and the discharge of the seeds from them. 

 To prevent such loss the seeds were collected before they became 

 too ripe. Many of the seeds did not mature, these later proving 

 to be unviable. The fluctuation in the number of seeds produced 

 by the separate females presents a wide variation. Some plants 

 have produced as low as one seed, whereas one of the females has 

 produced 230 seeds. Twelve females produced no^seeds. 



My first male plants were secured from the Brooklyn Botanic 

 Garden in November, 1914. Twelve plants in all were placed 

 among an equal number of females and permitted to cross freely. 

 Seeds set very profusely and several thousands were collected. 



In INIay, 191 5, the above seeds were sown in the experimental 

 plot of The New York Botanical Garden. Both male and female 

 plants in about equal numbers were produced. Over 700 male 

 plants were labelled and watched throughout the summer and 

 fall. The seeds from them are now being grown and the results 

 will be reported later. The males in general produce relatively 

 few seeds as compared with the females and more striking still 

 is the fact that less than 10 percent of all the males produced 

 any seed at all. 



The results so far secured confirm Strasburger's and bring out 

 very strongly the fact that there is a decided difference in the 

 seed production of such isolated individual plants. Strasburger 

 only indirectly called attention to the fact by giving the numbers 

 of seeds produced by each of his plants. The maximum number 

 produced by females under my observation was 230 seeds; the 

 maximum number produced l)y a male plant under my observation 

 was 47 seeds. 



In the January, 1916, "Proceedings of the National Academy 

 of Sciences" Goldschmidt rejjorts in a pr(liniiiiar\- paper upon 

 the sex-ratio in crosses between European and Jaj^anese races 

 of Gypsy moths iLymantria dispar). Me gets various gradation 

 in his sexes unlike the well-known gynandroiiiorphs. His indi- 

 viduals do not represent a mixture of the characters of the two 



