Algae. 237 



mulate metachromatin and correspond lo the "Centralkörner" of 

 Kohl, and those of the peripheral region accumulate cyanophycin 

 and correspond to cyanophycin granules. Chroococcus turgidus is an 

 example of this type; the number of metachromatin granules varies 

 greatly in different specimens; and, when the metachromatin is 

 excessive, it diffuses out into the ground substance; and then a 

 period of active division sets in The microsomes of the central 

 region mostly now react only with cytoplasmic stains. Division 

 occurs by the constriction of the cell into two approximately equal 

 halves, caused by the ingrowing cell- wall. Occasionally the central 

 reticulum stains a little more deeply, and the threads tend to be- 

 come drawn out in parallel lines without obliteration of the cross- 

 connexions. Metachromatin may represent a stage in the formation 

 of chromatin. 



In Gloeocapsa a deeper staining of the central network was usu- 

 ally, simulating the "spireme" stage. In Merisjnopedia elegans, a 

 higher type, there is definite 'central body' or 'nucleus' at the time 

 of division no real nucleus but an accumulation of chromatin at the 

 nodal points in a small central area of the cell. This accumulation 

 gradually disperses along the reticulum after the cell division. Di- 

 vision of this 'nucleus' takes place before it is reached by the in- 

 growing cell-wall. In Chroococcus macrococcus the highest type is 

 found. Here there is a definite 'nucleus' and cytoplasm. The inferior 

 of the 'nucleus' appears to be a Sap-vacuole; the peripheral part 

 stains deeply and contains a fine reticulum with chromatin at the 

 nodal points. The cytoplasm contains vacuoles. The plasmatic micro- 

 somes are very small and indistinct. 



The evolution of the nucleus and C3''tüplasm is suggested to 

 have taken place along the foUowing lines. The excess of food- 

 material elaborated by the pigment was first stored in the plasmatic 

 microsomes as a carbohydrate-cyanophj'cin. As elaborated material 

 increased, the central reserves became more complex, and the pro- 

 teid metachromatin granules were formed. In time the accumulation 

 of nucleo-protein became restricted to a small central region a tem- 

 porary 'nucleus', to ensure equal distribution on division {Merismo- 

 pedia). Later fas in Chroococcus macrococcus) the 'nucleus' became 

 Stahle and was always present; and a definite cytoplasm was esta- 

 blished. Ethel S. Gepp. 



Collins, F. S., The Marine Algae of Vancouver Island. 

 (Canada Geological Survey- Victoria Memorial Museum. Bulletin 

 NO. 1. Ottawa, p. 99—137. October 1913.) 



This is a list of all the marine algae hitherto collected on the 

 shores of Vancouver Island, with the exception of the ifvxojöAy- 

 ceae and Diatoniaceae. The novelties are Chantraiisia Macoiinii n. sp. 

 Gigartina exasperata Harv. and Bail. f. rnicrophylla nov. comb.; 

 Polysiphonia urceolata Grev. var. senticidosa nov. comb.] P.parasitica 

 Falk. f. borealis n. f., and f. luxurians n. f.; Ceramiunt rubrum Ag. 

 var. pacificum n. var. 



Valuable observations are made on geographica! distribution. 

 And a kej^ to the forms of Rhodomela and Odonthalia that occur 

 on the Pacific Coast is provided to facilitate their Identification. 



Ethel S. Gepp. 



