Dr. "W. Hofmeister on the Fecundation of the Coniferse. 439 



of the pollen-tubes bore no resemblance whatever either to 

 young pro-embryos of Taocus, or the cell-rosettes originating 

 together with them in the pollen-tubes, of which latter Schacht 

 possessed very elegant preparations. 



There cannot be the slightest doubt that the pro-embryo of 

 the AbietinecB may be observed as a simple cell impressed into 

 the lower concavity of the corpusculum ; the first division of this 

 cell taking place, as in Juniper-us, by a transverse wall. Very 

 often, the crosswise arranged longitudinal walls, which lay the 

 foundation of the construction of the pro-embryo out of four 

 longitudinal rows of cells, make their appearance only in the 

 lower of the two cells ; or the upper and larger of the two is 

 divided only once by a longitudinal wall. These cases, frequent 

 in Pinus Strobus and canadensis, contradict Schacht's view most 

 decidedly. Among the preparations which Schacht was good 

 enough to show me, I found one which exhibited a free cell- 

 rosette of four tough-walled cells in the upper concavity of a 

 corpusculum which had been halved by the section. In another 

 corpusculum of the same albumen, opened by the same cut, it 

 could be made out that the pro-embryo which had originated there 

 had already sent out embryonal tubes ^ of a line long. 



Whoever has made investigations on the fertilization of the 

 Abietinese, knows how surprisingly simultaneous, in all ovules of 

 the same species, is the passage through the exceedingly rapid 

 course of the first stages of development of the pro-embryo. I 

 may mention by way of example, that at Leipsic, in the present 

 year (1854), not a pollen-tube had penetrated to a corpusculum 

 on the 22nd of June, while only three days later, on the 25th of 

 June, among several hundreds of impregnated corpuscula that 

 were examined, not one could be found which did not contain 

 at least one 4-celled pro-embryo. I regard it as quite impossible 

 that one corpusculum can outstrip its neighbour by some twelve 

 days, in one and the same albumen, in the development of the 

 embryo. I look upon that preparation of Schacht's as an arti- 

 ficial product ; I believe that cell-rosette — perhaps the end-cells 

 of the embryonal tubes of the neighbouring corpusculum — must 

 have been carried, in slicing, into the impregnated corpusculum. 

 Such occurrences readily happen in making sections of objects 

 held between the thumb and finger. I possess a preparation of 

 Pinvs canadensis, in the opened, apparently otherwise undis- 

 turbed corpusculum of which, lies an epithelial cell from the skin 

 of the finger-tip. Other preparations of Schacht's exhibited, 

 beside the introduced end of the pollen-tube, two cells, flattened 

 by mutual pressure, appressed against the upper concavity of the 

 corpusculum- — germinal vesicles, such as I have already figured 

 in a similar condition in Pinus austriaca. Schacht has no ob- 



