Dr. W. Hofmeister on the Fecundation of the Conifene. 431 



in various states of development. Ordinarily however the pollen - 

 tube is torn off at the point where it fits the opening of the 

 corpusculum." 



It will be perceived that Schacht' s present description removes 

 two of the most important points of difference existing between 

 him and me. The untenable assertion, that in the Abietinese 

 the pollen-tube gradually fills up the corpusculum, and then pro- 

 duces the first cell of the embryo in its interior, is wholly re- 

 tracted. The young pro-embryo of Taxus is represented, in ac- 

 cordance with nature, as composed of parallel longitudinal rows 

 of cells, not drawn as formerly*, as a longish-ovate mass of 

 twelve-sided cells. The microscopical figures, the interpretation 

 of which is now in question, do not differ importantly from 

 what I have seen. 



In recent years, my researches have been almost exclusively 

 directed to the fecundation of the Conifers, in those few weeks 

 during which the most decisive stages of development are passed 

 through. I have especially endeavoured to make out the course 

 of development of those free cells which make their appearance 

 in the expanding pollen-tube, to which I directed attention on a 

 former occasion f. I have not yet arrived at a decision on this 

 point ; but on the other hand, I have complete observations 

 which make me regard the new views of Schacht as unfounded. 

 I publish the existing results of my later researches, in the hope 

 of stimulating some other observers to form an opinion on this 

 subject from their own observations, in the course of the next 

 few years. First of all, however, I will call attention to the two 

 facts, sufficiently established before, which stand in direct oppo- 

 sition to Schacht's present account, viz. the presence of nume- 

 rous free cells in the corpusculum before the arrival of the pollen- 

 tube, and the circumstance that the first cell of the pro-embrvo 

 may be observed, in all the three great divisions of the Coniferse, 

 as a simple cell (not originally as a rosette of cells) pressed into 

 the lower concavity of the corpusculum J. 



It is quite inexplicable how Schacht can question the first of 

 these conditions. The majority of observers, Mirbel and Spach, 

 Gottsche and Pineau, mention these cells ; Pineau has figured 

 them in Pinus sylvestris. The vacuoles, which appear earlier than 

 in the fluid contents of the corpuscula,a.nd which Schacht describes 

 quite correctly, have nothing in common with these cells. 



In the Abietinese, as in the Cupressinese, each corpusculum 



* Schacht, Entw. des Pflanzen-Embryon, t. 9. figs. 11, 13. 



t Vergleichende Untersuchungen, &c, p. 132 (1851). 



% Ibid. pp. 133, 136, 137. This stage of development, and still more 

 the preceding, of which I shall speak subsequently, are passed through so 

 rapidly, that their being overlooked is readily excusable. 



