PROGRESS OF MICROSCOPICAL SCIENCE. 



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granules. The following tables give M. Taniamschef s results in a 

 condensed form : — 



Tlie Surface of Botrydium granulatum. — Mr. E. Pigott has an 

 important paper on this plant in ' Grevillea' for January, 1873, giving 

 it the specific name of granulatum. He says that, " as Dr. Greville 

 and others have said, its surface seems minutely granular. Now this 

 I have ascertained by careful microscopic examination to be not ex- 

 ternal, although the effect is seen on the surface of the vesicles, but it 

 results from the pressure of the protoplasm and grains of chlorophyll 

 on the inside. The membranes composing the walls of the vesicles, 

 for there are two, an outer and an inner membrane, although this can- 

 not be ascertained with certainty, except at the base of the vesicles 

 and where the inner membrane begins to dry up when it shows in 

 folds, by carrying, and the breaking up of the endochrome, into folds 

 with it, and in the underground stems, where they are distinctly visible, 

 they appear to me to be perfectly structureless, that is, they are thin 

 transparent membranes only, without any cellular structure, and when 

 the plant is alive they remain distended to their very utmost from the 

 pressure of the fluid within. The young vesicle which, as will be 

 observed, only the swollen apex of a branch of the creeping or under- 

 ground stem, when it emerges from the ground it is frequently only 

 a clear transparent sac filled almost to bursting with a watery fluid ; 

 after a time minute green spherical grains will be seen, mostly adher- 

 ing in little groups to each other, and at length they take up their 

 position on the wall of the inner membrane, until the whole vesicle 

 appears to be filled with them ; but the vesicle being filled with them 

 is only in appearance, as it is only the walls that are covered, with a 

 few exceptions of granules floating in the fluid. When a full-grown 

 plant is pressed between slips of glass and examined, the membranes 



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