180 BASSOKINE SALEP CHLOROPHYLL. [BOOK i. 



gradually diffused throughout cold water. It is transparent 

 and soluble in hot and cold (?) water; in caustic alkali 

 is perhaps converted into an acid. It is not affected by 

 alcohol, ether, fatty or essential oils, and is not coloured by 

 iodine. On one side it passes by various modifications into 

 cellulose (ex. gr. the cell walls of Fucoids), and amyloid (ex. 

 gr. some kinds of horny albumen); on the other into amylum 

 (ex. gr. the mucilage of the Orchis tubers), and often further 

 into gum and dextrine. Probably Pectine and its compounds 

 are closely related here. (Henfrey.} 



3. Of Chlorophyll. 



To this is referred all the kinds of coloured granules 

 which occupy the interior of vegetable tissue. They have a 

 spheroidal, irregular figure, are often rather angular, and 

 consist of a semi-fluid gelatinous substance, which seems to 

 be a coagulum of the fluid contents of the cells. The colour 

 of plants, especially the green colour, is produced by the 

 presence of chlorophyll, which may be considered a vital 

 secretion. It will be mentioned more particularly in Book 

 II., in the chapter upon colour. 



According to Nageli, " the formation of chlorophyll takes 

 place in the leaves, and indeed always, after the formation of 

 starch. It seems to be produced in a similar manner to the 

 latter. In the parts of the leaf, which gradually become 

 green, we find within the cells, in addition to the starch 

 grains (which originate earlier), utricles in which a more 

 greenish matter is to be perceived, others containing three 

 or more green granules ; lastly, free chlorophyll granules 

 separate or adhering in clusters of from four to eight. Lower 

 down in the leaf occur only free chlorophyll granules in 

 company with starch grains. As the parent-cells of the 

 chlorophyll are only half the size of the starch, the investi- 

 gation is difficult, and conclusions are only possible from 

 analogy. I, however, believe myself entitled to assume 

 that the chlorophyll granules in Caulerpa originate, several 

 together, in separate mucilage-cells, which are afterwards 

 absorbed." (Annals of Natural History, xvii. 1 86) . According 



