STKUCTUHE OP CHLOROPHYLL GHANULES. 



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these lower animals. These cases of possible symbiosis deserve 

 and are receiving careful investigation. 



771. Many species of plants derive all or a part of tlie organic 

 matter required for llieir grovvtli and proper activities either from 

 other plants (when they are called parasites), or fi-om decaying 

 organic matters, such as vegetable mould (when tjjey are called 

 sapropliytes). In tlie tissues of a few such plants minute traces 

 of chlorophyll may sometimes be detected. 



772. Strncture of cliloropliyll granules. Under a moderately 

 high power of the microscope the granules appear as spheroidal ' 

 or polyhedral bodies, apparently homogeneous in structure, hav- 

 ing neither vacuoles nor granular matter. By the action of cer- 

 tain solvents it is possible to remove from the granule the pigment 

 which has imparted 



to it its characteristic 

 color, when tlie mass 

 remains without an}' 

 change of form. 

 Hence it is proper to 

 distinguish between 

 the cliloropliyll pig- 

 ment and the chloro- 

 phyll granule, each 

 of whicli will now 

 be considered. A 

 method recently dis- 

 covered makes it pos- 

 sible to demonstrate 

 the peculiar structure 

 of the granules with- 

 out complete removal 

 of the pigment. This 

 method, known as 

 Pringsheim's,^ depends upon the action of dilute hydrochloric 

 acid on the green parts of plants. When a thin green tissue, 



149 



1 In some of the Thallophytes, the whole or nearly the whole of the pvoto- 

 jilasraic mass seems to he evenly colored, presenting the appearance of coloi'ed 

 spirals, laniellffi, stellate fonns, etc.; anil snch colored masses are strictly chloro- 

 phyll bodies (Die Chromatophoren der Algen. Fr. Schmitz. Bonn, 1882). 



2 Pringsheim's Jahrli., xii., 1S79, p. 289. 



Fig. 149. Hypochlorii. ^, a cell of CEiogonium treated witli hyflrocliloric acid for 

 a few honrs; Ji, the paTie after some days: C, J>, E, needle-like forms; F, two cells nf 

 PrapernaVlia kept in liydrochlnric acid one month; G, cell of Anacharis in hydrochloric 

 acid after five montts' treatment, (Pringsheim.) 



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