REPORT OX VEGETABLE PARTHENOGENESIS. 153 



r 

 of the stigma, upon which Kadlkofer places so much roliano 

 proving the tact of non-impregnat ion, a Bgture ifl given (after \ i a ) 

 of the young j'ri'il still surmounted \,\ i he jjefefect stigma; and it is 

 stated that tlic stigma is not only persistent , hut c\cn increased in 

 growth after impregnation — a eircunirttance which (it is added) has 

 often been observed by Klotzseh in the Euphorbia< l 



Experiments upon Spinacia oleracra, simitar to those ju.-i men- 

 tioned upon MercuriaJis, led the autlior to the conclusion that 

 Spinacia is, in point of fact, an hermaphrodite plant, which can pro- 

 duce no perfect seeds when impregnation is really pre\on1cd, but 

 that such prevention is a most diilicult task, it being next to impos- 

 sible to remove the male tlowers at so early a stage and with so much 

 eare, as to be certain that impregnation has not taken place. 



Lastly, Kegel entered upon the same investigations with female 

 plants of Cannabis saliva. He eut the plants down to a few branches, 

 so that he might be able to examine with a lens the numerous flowers 

 which were daily produced, and so that the whole vegetative force of 

 the plant might be directed to those few branches, and thus favour 

 the formation of fruit. He kept these plants in favourable situations 

 until the month of October, up to which time none of the ovaries 

 produced seeds ; but all of them, without exception, withered and 

 dropped off. He then put these plants, and another female plant 

 subsequently reared, but not cut clown like the former, into a room 

 with a male plant. The heat of the room and other circumstances 

 he considered to be unfavourable to fructification. Nevertheless, the 

 female plants which had been cut doAvn produced and ripened seed, 

 whilst the other female plant did not fructify. The results are thus 

 recapitulated by the author. — Two plants cut dovni so that the whole 

 vegetative power was directed to the formation of seeds, placed under 

 favourable circumstances, vigorous in their growth, and having daily 

 access to fresh air, produced no fruit so long as impregnation was 

 withheld. The same plants under unfavourable circumstances, in 

 a close hot room, and when the days were shortened, produced and 

 ripened seeds as soon as they were subjected to impregnation. A plant 

 not cut down like the above, and impregnated under the (unfavour- 

 able) circumstances just mentioned, produced no seeds. 



Eegel states that he has not had the opportunity of examining 

 Ccelebogyne, and can therefore give no decided opinion as to that 

 plant. He suggests the possibility of the future discowrv of sessile 

 anthers between the bracts or near the glands, or that individual 

 pollen-grains may be developed in the interior of the embryo \ the 

 latter suggestion arising from the fact of Dccckc baring seen in 

 Ccelebogyne a pollen-tube which had penetrated to the embryo-sac, 

 although neither he nor Eadlkofer could discover pollen-grains upon 

 the stigma. 



Since the publication of Kegel's paper, Dr. Braim has returned 

 to the subject in a communication made to the Berlin Academy, and 

 published in their Transactions for 1859. This essay, which has 



