G22 SUMMARY OF CURRENT RESEAE0HE8 RELATING TO 



Binallcr as the distance from the central cell increases ; and these arc 

 coutimious with the ci)idermal cells. At the base of these larger cells 

 arc smaller ones of irregular shape, from which the hypha) of the stem 

 originate. The larger central cell is undoubtedly the initial cell of all 

 the rest ; it is a four-sided wedge-shajied cell, thu smaller and upper end 

 being rounded and the base truncated ; its longer diameter is at right 

 angles to the broad surface of the frond. 



The same general results were obtained in jP. vesiculosus and F. 

 filiformis. 



The preparations were made by preserving the fresh material in 

 alcohol of about 70 per cent., and imbedding in parafiBn, after staining 

 with various anilin dyes ; sections were then made in ribbons on a Jung 

 microtome, and mounted in balsam. 



Phycoerythrin.* — Herr F. Schiitt proposes the term rhodophyll for 

 the compound pigment of the red alga), limiting the use of phycoerythrin 

 to the jiortion soluble in water, while the portion soluble in alcohol he 

 calls Florideee-greeu. Corresponding to the terms chlorophyll and 

 rhodophyll, w^e shall then have phoeophyll for the chromophyll of the 

 Phffiophyceje, cyauophyll for that of the Cyanophycese, melinophyll for 

 that of the Diatomaeeae, and pyrrophyll for that of the Peridinea;. In 

 the same manner, the portion soluble in alcohol is composed of chloro- 

 phyllin and of the various forms of xanthophyllin found in the different 

 gi'oups, viz. phycoxanthin, diatomin, and peridiniu ; while the 2>igtnents 

 soluble in water may be termed phycoerythriB, phycophajin, and phyco- 

 pyrrin. 



The absorption-spectrum of a solution of phycoerythrin is described 

 in the cases of extracts of Ccramium rubruni and Dumontin fiUformis. 



Procarp and Cystocarp of Gracilaria.j — Mr. T. Johnson finds that 

 the position of the hitherto undetected procarp in Gracilaria confer- 

 voides is indicated by a lateral swelling. The procarp consists of six or 

 seven cells, distinguished by general arrangement, size, and contents 

 from the surrounding cells of this swelling. From an apical and usiially 

 smaller cell of this group arises the trichogyne, which, after a more or 

 less circuitous course within the swelling, reaches the external surface, 

 on which it projects, exposed for contact with the " spermatium." The 

 pericarp is, in Gracilaria, formed before fertilization, and, together with 

 the procarp and placenta, arises by repeated periclinal division of the 

 two or three outermost cortical layers of cells of the swelling. 



The act of impregnation exhibits several remarkable peculiarities. 

 The cells both of the procarji and of the placenta coalesce with one 

 another by the disappearance of their cell-walls ; and the fused cells of 

 the procarp and of the placenta are placed in communication with one 

 another by protoplasmic protrusions (diverticula), proceeding from the 

 fused cells of the procarp and passing through their swollen walls. The 

 cells forming the free surface of the placenta now produce radiating 

 rows of basipetally formed spores ; while from the fused procarpial cells 

 other diverticula arise, which also form spores at their free ends inde- 

 pendently of the placental cells. 



The author suggests that the nucleus resulting from the impregnation 

 of the trichogyne by the " spermatium," fuses in turn with the nuclei of 



* Ber. Dciitsch. Bot. Gcscll., vi. (1888) pp. 36-52 (1 pi.), 

 t Ann. of Bot., i. (18S8) pp. 213-22 (1 pi.). 



