STRUCTURE OP CHLOROPHYLL GRANULES. 



289 



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 the organic 

 matter required for their growth and proper activities either from 

 other plants (when they are called parasites), or from decaying 

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

 saprophytes). In the tissues of a few such plants minute traces 

 of chlorophyll may sometimes be detected. 



772. Structure of chlorophyll granules. Under a moderately 

 high power of the microscope the granules appear as spheroidal l 

 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 the mass 

 remains without any 

 change of form. 

 Hence it is proper to 

 distinguish between 

 the chlorophyll pig- 

 ment and the chloro- 

 phyll granule, each 

 of which 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, 2 depends upon the action of dilute hydrochloric 

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



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

 plasmic mass seems to be evenly colored, presenting the appearance of colored 

 spirals, lamellae, stellate forms, etc. ; and such colored masses are strictly chloro- 

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



2 Pringsheim's Jahrb., xii., 1879, p. 289. 



FIG. 149. Hypochlorin. A, a cell of CEdogonium treated with hydrochloric acid for 

 a few hours; K, the same after some days: C, D, E, needle-like forms; F, two cells of 

 Drapernalrtia kept in hydrochloric acid one month; Q, cell of Anacharis in hydrochloric 

 acid after five months' treatment. (Pringsheim.) 



19 



