ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 667 



of cytoplasm and starch-grains, round the periphery of which a mem- 

 brane is formed. After the tip of the tube has reached the depression 

 above the archegonium complex, the body-cell divides to form two male 

 cells, which enter separate archegonia. 



From twelve to sixteen macrospores are formed, but only one ger- 

 minates and forms the female gametophyte. No distinct tapetuui is 

 present. In the formation of the prothallium the wall becomes lined 

 with a parietal layer of primary prothallial cells, which become multi- 

 nucleate, and by their inward growth the large central vacuole becomes 

 ultimately filled up. The cell- walls are formed as the result of a peculiar 

 method of free-cell formation. The archegonium-initials appear as 

 peripheral cells just before the prothallial tissue is thoroughly organised. 

 There are four neck cells, and a ventral canal-nucleus is cut off before 

 fertilisation. The archegonia are arranged as in the Cupressese, in a 

 single group at the apex of the prothallium. They are surrounded by 

 a common layer of jacket-cells, which are multi-nucleate, their characters 

 suggesting that they are sterile archegonia. 



A single male cell enters the egg ; the first segmentation spindle is 

 organised in the centre just about the place where the fusion of the 

 sex-nuclei occurred. After the second division the four free nuclei pass 

 to the base of the archegonium, become arranged in two tiers, and 

 undergo a third division, and an embryo consisting of two tiers of cells 

 and one of free nuclei is organised. The middle tier forms long tor- 

 tuous suspensors, which carry down the embryo-cells at their tips. One 

 or several embryos may be developed from a single archegonium. 



As nearly as could be estimated, there are nine or ten chromosomes 

 in the nucleus of the gametophyte, and eighteen or twenty in that of the 

 sporophyte. The gametophytes and embryo of Cryptomeria are distinctly 

 of the Cupressege type. 



Gametophyte and Development of the Seed-coats in some 

 Papaveraceas.* — C. H. Shaw gives the results of his examination of 

 some quantity of material of San guin aria, CheUdonium and Esch- 

 scholtzia. He finds that in Sanguinaria the microspore mother-cells are 

 formed in the season preceding blooming, but their division and the 

 formation of the ovular integuments and of the embryo-sac occur after 

 renewal of growth in the spring just before blooming. In all genera 

 an open canal extends from the carpellary cavity to the exterior. The 

 antipodal cells are very prominent, especially in Eschscholtzia, and the 

 adjacent cells of the nucellus are thick-walled and rich in contents. 



In formation of the seed-coat in Sanguinaria and Eschscholtzia, the 

 secundine eventually disappears, and the inner cell-layer of the primine 

 constitutes the most important element of the testa. In Ghdtdonium 

 both primine and secundine persist and take part in the formation of 

 the testa. 



Physiology. 



Nutrition and Growth. 



Sources of Nitrogen to Fungi.j — J. H. Kastle and E. Elvove find 

 that a nutritive solution containing ammonium thiocyanate as the 



* Bull. Torrey Bot. Club, xxxi. (1904) pp. 429-33 (1 pi.). 



t Auier. Ciiem. Journ., xxxi. (1904) pp. 550-7. See also Journ. Chen. Soc. 

 Ixxxvi. (1904) II., pp. 504-5. 



