416 BOTANICAL GAZETTE . [may 



' 



thallus, sometimes is found only around the margin and on the under side of the 

 lobes, and sometimes is wanting entirely. 



Muenscher reports a list of marine algae found on Shaw Island (one of 

 the San Juan group) , with notes as to zonal distribution and relative abundance, 

 and a discussion of the ecological factors involved. He finds 54 Rhodophyceae, 

 31 Phaeophyceae, 15 Chlorophyceae, and 3 Myxophyceae. The plates give 

 the distribution at various points on the island and will be very useful to col- 

 lectors of algae in the region. 



Miss Kibbe reports the presence of a parasitic fungus {Chytridium alarium, 

 sp. nov.) on Alariafistulosa collected in Alaska. She examined all of the species 

 of brown algae that were readily available at the Puget Sound Marine Station, 

 and also specimens of Alaria valida from Alaska, and did not find any trace of 

 this fungus in any of them. In A . fistulosa she found the fungus in various 

 forms in all parts of the plant except the heavy older portions of the stipe. 



Miss Karrer finds that some light is thrown on the metabolism of Nereo- 

 cystis by chemical reactions whose results are seen under the microscope. 

 She finds that the cell walls are made up of cellulose and algin, the latter being 

 probably the substance that holds the cells together. She finds that the 

 presence of the inorganic substances (calcium, magnesium, sodium, potassium, 

 chlorine, sulphates, carbonates, phosphates, and iodine) whose presence in the 

 plant have often been shown by analytical chemists can be demonstrated in the 

 cell by using the methods suggested by Tunmann 3 and Molisch 4 with slight 

 modifications. 



Miss Clark reports the acidity of marine algae as determined by titration. 

 She reports that all of the 3 1 species tested were acid. 



Langdon 5 finds that carbon monoxide is present in the float of the bladder 

 kelp (Nereocystis), the quantity varying considerably in different individuals. 

 He finds the presence of carbon dioxide to be only occasional and the quantity 

 minute. He does not find confirmation of previous work tending to show 

 that the quantity of carbon dioxide and of oxygen vary with the time of day. 

 He suggests that since theories of photosynthesis have largely been concerned 

 with carbon monoxide and its reduction product formaldehyde, and with 

 formic acid, of which carbon monoxide may be considered the anhydride, it is 

 possible that the occurrence of carbon monoxide in plant tissues may be more 

 general than has been supposed. Apparently Langdon's work is the first 

 demonstration of free carbon monoxide in a living plant. A large plant cavity 

 surrounded by rapidly growing tissue furnishes an unusually favorable oppor- 

 tunity for the investigation of gases taking part in metabolism. The sieve 

 tubes in this plant are in the mycelium-like pith web on the interior surface of 



3 Tunmann, O., Pflanzenmicrochemie. Berlin. 1913. 



4 Molisch, H., Microchemie der Pflanzen. Jena. 1913. 



s The substance of this paper has also been published in Jour. Amer. Chem. Soc 

 39:149-156. 1917. 



