258 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



Algae. 



Phycoerythrin.* — Herr P. Schiitt has found, by a combination of 

 Eeinke's spectropbore with Zeiss's microspectroscope, that the intense 

 orange-yellow fluorescence of phycoerythrin belongs only to a light with 

 the wave-length between A = 590-560, and that only rays between A = 

 600-486 can produce a powerful fluorescence, a smaller degree being 

 caused by rays between A = 490-470. The maximum of absorption and 

 of the power of producing fluorescence concur. 



Besides the normal blue-red a phycoerythrin, which can be 

 obtained from algae directly by extraction with water, Herr Schiitt has 

 obtained two derivatives wbich he calls jB phycoerythrin and y phyco- 

 erythrin. The former is pure red instead of blue-red, and is obtained 

 by the action on a phycoerythrin of such neutral substances as alcohol, 

 barium chloride, &c. ; the latter is violet-blue, and is obtained by pre- 

 cipitation by acids from the normal pigment. 



The author regards phycoerythrin as a chromatophore-pigment quite 

 distinct from chlorophyll and its derivatives. 



Reproductioii of Sphgerococcus.f — Mr. T. Johnson describes the 

 hitherto unknown procarp of Sphserococcus coronopifoUus. The main 

 stem produces irregularly placed branches, from which very numerous 

 short flat branchlets spring in an upward direction ; and these branchlets 

 have their two edges beset with small cylindrical filaments. Eunning 

 through the middle of each filament is a central axis consisting of a 

 uniseriate row of large tubular cells. In these cylindrical filaments or 

 procarp-branches are formed the procarps which are very numerous. 

 Any primary lateral branch of the central axis may develope a procarp. 

 The carpogenous branch consists of three cells, the apical cell of which 

 is the carpogone and developes the trichogyne, which is exceedingly long 

 and reaches the surface of the thallus after curving in all directions. 

 The procarp is completed by the formation of a number of small 

 secondary lateral branches, the carpogenous cells. Contact of the 

 " spermatia " (poUinoids) with the trichogyne was not actually observed. 



The course of development of the cystocarp is as follows : — After 

 fertilization the carpogone fuses with the hypogynous cell, and this 

 apparently with the basal cell of the carpogenous branch. Further 

 fusion then takes place with cells of the lateral branch and of the 

 central axis in succession, and a large conjugation-cell is thus formed, 

 from the greater part of the surface of which ooblastema-filaments arise 

 even before the process of fusion is completed. These filaments are 

 short, and composed of but few cells, the terminal one or two of which 

 become carpospores. The carpogenous cells also become connected 

 directly with the large conjugation-cell, and produce carpospores at their 

 apices. As the cystocarp developes, its presence is manifested by a 

 spherical swelling in the frond, and the carpospores ultimately escape 

 through an irregular slit in the pericarp, not through a definite pore. 

 Each cystocarp is the product of one procarp only. All the cells which 

 fuse with the carpogone to produce the central cell of the cystocarp are 

 auxiliary cells. 



If Gracilaria and Nitophyllum are united with Sphserococcus to form 



* Ber. Deutsch. Bot. Gesell., vi. (1888) pp. 305-23. 

 t Ann. of Bot., ii. (1888) pp. 2li3-304 (1 pi.). 



