14 Stopes and Pujii, The nutritive relations of the Burrounding tiasues etc. 



anil'act <>r as abnormal phenomena. In the course of nur work 

 wc haye oever observed any such phenomena in materiaJ fixed in 



alcohol QOI in that fixed in Flcmniing's Solution. 



Structure of the wall of the central cell (later 

 egg cell and ventral canal cell) in Cycads, 



Ginkgo and Pinus. 



As the structure of the egg cell membrane in these three 

 groups is the same in all essentials, it will he more convenient to 

 consider theni together. 



1>\ the tinie of Miquel 1 ) and Warming 2 ) the real nature of 

 the egg-wall was not realised, although they noted that it was thick 

 and pitted. The writers of the next period 3 ), 4 ) figured a membrane 

 closing the deep pits on the side of the jacket cells, and the 

 results of our present close examination have led us to confirm this 

 vicw and not that of the more recent Avorkers, eg. Ikeno 5 ), 

 Coulter and Chamberlain 6 ), Smith 7 ) and others w r ho represent 

 in their works merely broad open Communications through the very 

 thick egg membrane. Goroschankin's description is remarkably 

 detailed and accurate. He noted that closing the deep pits of the 

 thick wall of the egg is a fine membrane which is itself somewhat 

 irregularly thickened and perforated in a way comparable to a sieve 

 plate. He missed the final pit closing membrane however, and took 

 the filling plasma of the smaller pits to be actual open Communi- 

 cations of cytoplasm between the egg cell and jacket cells, so that 

 bis "sieves" are comparable to sonie of Kienitz-Gerloff s s ) 

 thicker Plasmodesmen in other plants which were pointed out by 

 Meyer 9 ) not to be open Communications but merely the pit filling 

 plasma on either side of a fine lamella. 



2 ) Miquel, F. A. W., „Nouv. mat. p. servir ä 1. conn. d. Cycadees-'. 

 (Archiv. Neerland. III. 1868. p. 193—254. see p. 209 and pl. XI. fig. 6.) 



2 ) Warnung, M. E., „Recherch. et remarques s. 1. Cycadees". (Overs. o. d. 

 Kon. Dan. Yid. Selsk. 1877. freneh resume p. 16 — 27.) „Contrib. ä l'hist. nat. 

 d. Cycadees". (Overs. o. d. K. D. Vid. Selsk. 1879. resume 9—12. pl. VI. 

 fig. 6 and 7.) 



3 ) Groroschankin. J., ,.Zur Kennt, d. Corpusc. b. d. Gymnospermen". 

 (Bot. Zeit, 1883. p. 825—831.) 



4 ) Treub, M., „Eecherch. s. 1. Cvcadees". (Ann. d. Jard. d. Buitenz. 

 Vol. IV. 1884. pl. II. fig. 7—8.) 



5 ) Ikeno, S., ,. Unters, ü. d. Entwick. . . . b. Cycas revoluta". (Jahrb. f. 

 wiss. Bot. XXXII. 1898. p. 557—597. see PI. VITL) 



e ) Coulter, J. M.. and Chamberlain, C. .1., „Morph, of Spermato- 

 phytes. PI. I. Gymnosperms". New York 1901. p. 22. 



7 ) Smith, I. S., ..Nutrition of the egg in Zamia". (Bot. Gaz. Vol. 37. 

 1904. p. 346—352.) 



8 ) Kienitz-Gerloff , F., „Die Protoplasmaverbindungen zw. benach- 

 barten Gewebselementen in d. Pflanze". (Bot. Zeit. Jahrg. 49. 1891. parts 1—6 

 begin. p. 1.) 



9 ) Meyer, A., „Das Irrthümliche d. Angaben ü. d. Vork. dicker Plasma- 

 verbindungen zw. d. Parenchymzellen einiger Filicineu u. Angiospermen". 

 (Bericht, d. D. Bot. Ges. XIV. 1896. p. 154—158.) 



