98 PROCEEDINGS OF THE ACADEMY OF [1899. 



does not explain liow cotyledouous seeds are coustructed in this 

 way. 



In 1894 the autlior of this paper decided to make for himself 

 oareful observations on Riciniis. A number of plants were set out 

 in a mass where he could easily watch thein. Every male bud that 

 could be observed was rubbed away before expansion. For all this 

 an abundance of seed matured. It was found subsequently that 

 there were other plants within a quarter of a mile. It was thought 

 best to repeat the observations another year. The following year 

 no plants were near but those under observation, and it began to 

 look as if the plants had no use for pollen. Still there seemed 

 doubt, and the observations were continued yearly to the end of 

 1897 — all w^ith the same result. Dr. Ida A. Keller, Professor of 

 Biology in the Philadelphia Girls' High School, an experienced 

 microscopist, aided me considerably in the observations made, and 

 only for the fact that in one of her acute examinations she discov- 

 ered a pollen tube at work on the ovarium, there would have 

 seemed no room for doubt that pollen was unnecessary for the pro- 

 duction of perfect seed in Rieinu><. It was determined to try once 

 more. The past year, 1898, only one plant was allowed to grow, 

 tvud only one flower spike permitted to remain. All the others 

 ^vere cut away in the bud. This permitted closer examination, 

 which was made almost daily. I noted for the first time that there 

 were on the pedicels with the female flowers, buds scarcely larger 

 than pin heads, and, under a strong lens, evidently autheriferous. 

 These wei*e carefully cut away. As the female flowers opened 

 iihey all withered, unlike their fertility in former years. There 

 seemed no doubt that pollen was essential. After half the spike had 

 fallen away, the upper portion, say some twenty flow'ers, showed 

 n disposition to permanence. The pretty fringed pistils protruded 

 and continued perfect for many days. Finally, the capsules en- 

 larged until they had about reached the usual dimensions. Now it 

 seemed as if the plant would produce seed without the aid of 

 pollen. After turning brown and seemingly ripe they were found 

 to be as empty as Camerarius' mulberries were. 



While under the impression during the earlier years of these 

 t)bservations'that Ricinus was fruiting in the absence of j)ollen, I 

 was encouraged by observations seemingly confirmatory by Judge 

 Day, of Buffalo, and Prof. Greene, of Washington, on other 



