iv Proceedings. [October jist, igo^. 



that including tlie pine trees, Ginkgo, and the Cycads, viz. : — 

 the Gymnosperms. Though the egg cells in this group are in 

 many ways different from those of the flowering plants, the 

 results have some bearing on the question of nutrition of egg 

 cells in general, as well as some points of general technique. 



The egg cells in all the plants under consideration are 

 surrounded by a well marked layer of cells, called the "jacket 

 cells." In the past, it has been stated by Arnoldi, Ikeno, 

 Coulter, and Chamberlain, and others that the nuclei of these cells 

 enter the egg cell either bodily or in part, and so provide 

 nourishment for the growing egg. The " proteid vacuoles " in 

 the egg of Finns and the proteid granules in Ginkgo and Cycas 

 had been traced directly or indirectly to these nuclei. 



The author shows that the entry of these nuclei does not 

 usually take place, and that the structure of the wall of the egg, 

 in which a fine membrane closes all pits, makes it impossible 

 under normal conditions ; and that it is not necessary to look 

 only to the nuclei of these jacket cells for the supply of proteid, 

 as the whole surrounding tissue in Ginkgo and Cycas is packed 

 with absolutely similar proteid grains to those in the egg. It was 

 also found, during research in an Alpine laboratory, where the 

 author examined living material every three hours during the 

 day, that starch grains occur in the egg cell as well as in the 

 surrounding tissue. The author lays stress on the fact that 

 carbohydrate (/.(?., starch) always travels in soluble form as sugar ; 

 that proteid also travels in some soluble, simpler form ; and that 

 it is unnatural to expect a sudden change in the mode of entry 

 to the egg, as would be the case if the nuclei of surrounding 

 cells entered it as such. 



The jacket cells act as a secreting layer and dissolve the 

 food stored in the endosperm, which then passes into the egg in 

 the normal way in solution. 



In conclusion, the author states that the past unnatural 

 views have probably resulted from too close attention to material 

 treated by elaborate technical methods, and that her work on 

 treated material was always checked by work on living material. 



