ALGAL UTILIZATION 453 



and it is likely to become even more important in the future. 

 Chlorella is rich in proteins, fats and vitamins, and in the presence 

 of nutrients, CO 2 and sunlight, multipUes at an enormous rate. 

 Several countries have been experimenting with the mass produc- 

 tion of Chlorella. Pilot scale Chlorella 'farms' have already been 

 estabhshed in America, Japan, Holland, Germany and Israel. Such 

 farms do not require excessive amounts of water and hence would 

 be invaluable to augment food supplies in arid areas. Such Tarms' 

 on a smaller scale could also be used to supply food in space 

 stations of the future and even in large space ships. 



Chlorella is also being increasingly used as a means of purifying 

 sewage. When it is present in large, shallow tanks of effluent (after 

 primary sedimentation of soUds) the rapid photosynthesis produces 

 abundant oxygen which is then used by the bacteria responsible for 

 destroying the remaining organic matter. A number of sewage 

 works using Chlorella now exist in the U.S.A. and at present the 

 largest in the world is operating at Auckland in New Zealand. It 

 would seem that this cheap and effective means of sewage purifica- 

 tion is likely to extend in the future. 



REFERENCES 



Chapman, V. J. (1950). Seaweeds and their Uses. Methuen. 

 Burlew, J. S. (1953). Algal culture from Laboratory to Pilot Plant. Cam. 

 Inst. Wash. Pub. 600. 



ADDENDUM 



A recent monograph by Starr on Chlorococcum indicates that C. humicolum 

 is a doubtful species because of the original inadequate description. Starr 

 recognizes nine species, mostly from soil. 



A recent treatment of the Ulvaceae (Papenfuss) transfers species of 

 Gemina and Lohata (see p. 56) to Ulva. 



Tribonema bombycinum (p. 263) is now named T. viride. In a recent 

 revision of the coccoid Myxophyceae^ Drouet and Daily take the view that 

 there is great morphological variation and many of the genera and species 

 formerly described are merely different growth forms of a single species. 

 Microcystis and Chroococcus are both placed in the genus Anacystis. M. 

 aeruginosa and M. toxica are regarded as synonyms for Anacystis cyanea; 

 Chroococcus turgidus and probably also C. macrococcus of Crow (fig. 162) 

 are synonyms for Anacystis dimidiata. Merismopedia becomes a synonym 

 for Agmenellum and both M. aeruginosa and M. elegans are referred to 

 A. thermalis and M. ichthyolabe to Anacystis cyanea. The genus Gloeothece 

 (pp. 281, 296) is treated as synonymous with the genus Coccochloris. On 

 p. 413 Synechococcus elongatus becomes Coccochloris elabens and Synecho- 

 cystis sp. becomes Anacystis sp. 



