268 University of Calif orma Publications in Botany [Vol. 5 



mature normal seeds without pollination either accompanied by the 

 supposed stimulation of mutilation or not. First the production of 

 phenospermic seeds. Second, the production of phenospermic seeds 

 which contain a greater or lesser amount of cellular structure, rich in 

 starch and proteid, and taken to represent endosperm (cf. Woodburn, 

 1911, etc.). Third, the production of seed normal in appearance, con- 

 taining endosperm and embryos fully developed and capable of germi- 

 nation and initiating the growth of normal seedlings. To my mind the 

 production of a considerable number of parthenocarpic fruits contain- 

 ing phenospermic seed is the most significant result of the experiments 

 above described. I desire again to call attention to the iwssihility 

 that after one or two years of further cultivation in our cultures, 

 the large proportion of phenospermic seeds with or without embryos 

 may be lessened in favor of a greater proportion of entirely normal, 

 viable seeds resulting from the castration or mutilation of flowers of 

 "Nic. tahaccum Cuba." I feel, also, that this variety of N. Tahacum 

 by its rather ready parthenocarpy and phenospermy as it was grown 

 in our cultures this past year, and entirely apart from such cases of 

 parthenogenesis as were found, furnishes a partial confirmation of 

 Mrs. Thomas' results in similar experiments on plants of the same 

 variety. I fully understand that this is practically equivalent to 

 the statement that the difference in soil and possibly general climatic 

 conditions between England and California will account for the small 

 amount of parthenogenetic seed obtained in the experiments above 

 described as contrasted with the frequent and ready production of 

 such seed by the same plants as grown by Mrs. Thomas. Nothing 

 that has been said, however, must suggest that I desire to confirm 

 her general experimental results; results which she feels indicate 

 that parthenogenesis is peculiar to Nicotiana species in general. It 

 must, on the contrary, be emphasized that our general results point 

 to exactly the reverse condition and that we have no reason to suppose 

 that parthenogenesis has occurred in any of our previous cultures. 

 Speculation, also, as to the time at which and the way in which 

 parthenogenesis, parthenocarpy and phenospermy arise in " Nic. tabac- 

 cuni Cuba" must be of little significance until pertinent cytological 

 data can be accumulated. I have, further, no suggestion to offer, at 

 the present time, as to the possible origin of this Nicotiana Tabacum 

 variety which exhibits such marked divergence from the restricted 

 method of fruit and seed production peculiar to other varieties of 

 this species and to all other species of tobacco so far as known. 



