Stop es and Fujii. The nutritive relations of the surrounding tissues etc. 5 



series treated with Iodine yielded particulaiiy instructive results 

 when compared with similar series stained with Triple stain, 

 especially as regaxds the starch and protein grains. For the 

 detectiou of "Plasmodesmen" we chiefly used hand sections of 

 90 % spirit material. 



In short we used as many kinds of material as were available, 

 checking the results obtaiued from hand sections of fresh material 

 with those of microtome series whenever possible. 



Observations. 



Cycads. 



Tlie general appearance of the Cycadean prothallium, with its 

 large archegonia, is too well known to require special description. 

 The cells of the prothallium immediately surrounding the egg cell 

 differ somewhat in appearcance from the others and have long 

 been known ander the name of "jacket" or „sheath" cells. In all 

 the Cycads we have examined these cells appear to be simply 

 modified cells of the prothallium, and no facts have come to light 

 in our work to snpport Lawson's 1 ) view (expressed for Sequoia 

 and Crypto?iieria) that they are reduced sterile eggs. This however 

 does not affect their physiological relation to the egg cell which is 

 onr present consideration. 



The facts that the ir cytoplasm is very thick and granulär, 

 and their nuclei are frequently twice or more in diameter those of 

 ordinary endosperm cells (see fig. 8) alreadv indicated the 

 pysiological importance of the jacket cells, which we must discuss 

 later after various details have been brought forward. 



In the course of this paper we will attempt to describe the 

 observations made on the nature of food stuffs entering the 

 Archegonia (not only the protein granules to which most authors 

 confine their attention, but also carbohydrates etc.), the form in 

 which these food stuffs travel, and the mode of their passage 

 through the cell walls. 



The youngest fresh material of Cycads which we have examined 

 was Ceratozamia fusco- viridis, in which the egg cells were only just 

 recognisable with the naked eye. By this time starch was laid 

 down in the integuments, and to a slight extent in the nucellus, 

 but the thin walled, hyaline endosperm tissues were entirely devoid 

 of it. On testing whole endosperms with Fehling's Solution, strong 

 reduction took place as was seen by the considerable formation of 

 cuprous oxide; this reaction, although suggesting the presence of 

 sugar is not necessarily conclusive, as there is a strong "reducing 

 substance" 2 ) other than known kinds of sugars, present in large 



') Lawson, A. A., ..The gametophytes. archegonia. Fertilisation and 

 embryo of Sequoia sempervirens" . (Ann. of Hot. Vol. XVIII. 1904. p. 1 to 28. 

 see p. 15.) ..The guinet., fertiliz. and emb. of Cryptomeria Japonica" . (Ann. 

 of Bot. Vol. XVIII. 1904. p. 417 to 444. see p. 431.) 



-) Fujii. K.. „Ueber d. Hestänbungstropl'en d. Gymnospermen". (Berichte 

 d. I). Bot. Ges. Bd. XXI. 1903. Heft 4. p. 815.) ' 



