CONCERNING THE PRESENCE OF ‘DIASTASE IN 
CERTAIN RED ALGAE 
E. T. BARTHOLOMEW 
Introduction 
In most starch-forming plants the starch grains are deposited 
in the plastids. The work of both early and recent investigators 
shows, however, that this is probably never true for the red algae. 
In this group of plants the grains are described as being formed in 
the cytoplasm, outside the plastids and often apparently quite 
independent of them. 
In the red algae the grains, which resemble the starch grains of 
higher plants, do not usually give the customary blue color when 
treated with iodine or zinc chloriodide. In a few species, for 
example Lorencia sp., Polysiphonia nigrescens, and Ceramium 
tenuissimum,: the color with iodine varies from violet to almost 
blue, but in most species it ranges from light brown to wine red. 
There is such a wide divergence of reaction in the different forms 
tested that OLTMANNS? suggests the possibility that each species 
will be found to give its own characteristic color reaction. 
Saki’ found that by applying strong solutions of malt extract 
to commercial food preparations made from various red algae, such 
as Gelidium sp., Porphyra sp., and Chondrus crispus, no digestion 
whatever of the carbohydrates took place. From this and other 
experiments he concludes that the polysaccharid carbohydrates 
in these algal food preparations are not readily transformed into 
sugar by carbohydrate-digesting enzymes of animal: origin, and 
scarcely more so by vegetable enzymes or bacteria. 
Konic and Betrets* hydrolyzed, with acids, the carbohydrates 
in Porphyra sp., Gelidium sp., and commercial compounds com- 
* OLTMANNS, F., Morphologie und Biologie der Algen 2:148. 
2 [bid. 
3 Sark, T., The digestibility and utilization of some polysaccharid carbohydrates 
derived from the lichens and red algae. Jour. Biol. Chem. 2:251-265. 1906. 
4 Konic, J., and — J., Die Kohlenhydrate der Meeresalgen und daraus: 
hergestellter Erzeugnisse. Zeitschr. Untersuch. Nahrungs- und Genussmittel 10: 
457- 1905 ; 
Botanical Gazette, vol. 57] [136 
