ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 605 



as iridescent by some authors. Kylin finds that albumen plays no part 

 in the cell-contents, but agrees with Molisch that a labile chemical 

 combination is present which easily throws off iodine. When the plant 

 dies, these " Blasen-zellen " burst, the contents come out and the iodine 

 stains blue any starch solution, and leaves a blue mark on paper. The 

 author surmises that the cells act as a protection agaiust small animals, 

 particularly small molluscs which eat alga?. In Spermotliamnion 

 roseolum almost every cell bears on its upper transverse wall one of 

 these "Blasen-zellen." They vary from 8-10 fx and appear to have 

 the same cell-contents as those of Bonnemaisonia asparagoides. In 

 Centillium tenuissimum the "Blasen-zellen" contain an elongated pris- 

 matic albumen-crystal, occasionally two or three. The number of these 

 cells in the different cortical rings of a branch varies greatly, sometimes 

 none, sometimes as many as ten being present. In this alga the cells 

 contain albumen-crystals and no iodine. These albumen-crystals prob- 

 ably play some part in the nutrition, possibly during the development 

 of spores, since the " Blasen-zellen " are known to disappear in later 

 stages of the alga. The " Blasen-zellen " of Antithamnion plumula 

 have been already described by Nestler. In their upper part one com- 

 monly finds several small chromatophores lying embedded in a little 

 protoplasm. The cell-contents are colourless and strongly refractive. 

 Under a weak magnification they appear to be homogeneous ; under 

 stronger magnification, however, there is seen a peculiar, finely-granular 

 structure. The contents are albuminous, and no iodine was found. 

 Various authors attribute various functions to these cells. Kylin is 

 unable to make any decided statement, and refrains from adding to the 

 many surmises. 



Oceanic Algology.* — A. Mazza continues his studies of marine 

 algae. He discusses Blastophye, a genus of doubtful affinity, with one 

 Australian species ; and then begins a review of the family Dumontiaceaa, 

 describing the structure and characteristics of the typical species of 

 Dumontia (1 sp.), Crypto svphonia (2), Dudresnaya (4). 



Kelps of West Coast of America.f — F. K. Cameron publishes a 

 report entitled " Potash from Kelp," in which are included papers by 

 himself and others on the production of potash for agricultural purposes 

 from the large kelp beds in the United States. With few exceptions, 

 the supply of this element has always come from the German mines ; 

 but the present report shows that the United States could produce its 

 own supply. Of the large number of alga3 growing on the Pacific 

 coast, only three species seem to offer any particular promise of im- 

 portance as possible commercial sources of potash salts, since, besides 

 having a high potash-content, they grow in open water and can be 

 easily harvested. They are Macrocystis pyrifera, Nereocystis liitkeana, 

 and AJaria fistulosa. 



The large kelp beds are reported on by specialists. Those from 

 Lower California to Paget Sound were investigated by W. C. Crandall 



* La Nuova Notar., sxvi. (1915) pp. 133-54. 



f U.S. Dept. Agric, Report No. 100 (1915) 122 pp. (40 pis. and tables). 



