128 
A very searching examination shewed that the sample did 
notcontain any other organisms than Huglenidae, chiefly E. viridis, 
but with a few of H. deses and Phacus triqueter. Mr Hotuanp then 
proceeded to the examination of the bulk of the gathering, 
which had, I believe, been obtained from an old tub of rain 
water in the vicinity of Stroud. He extracted the colouring 
matter with alcohol, ether, and also with castor oil, and 
obtained by spectroscopic examination the characteristic bands 
of the green colouring matter of plants. He went a step 
further than this—he separated out from the alcohol solution 
the yellow colouring matter Xanthophyll, one of the constitu- 
ents of the compound colour Chlorophyll. Although I had 
only a small quantity of the gathering, I proceeded to the 
examination of the evolved gases under the action of light, 
and, by an experiment used in the examination of plants, 
determined the evolution of free oxygen. 
I searched diligently for starch, but without success, the 
so-called amylaceous bodies of Savirte Kenr giving no starch 
re-action. We were unable to obtain a further supply of the 
animal in such a pure state, so our further researches were 
postponed. We might have proceeded to separate out the 
varieties of Chlorophyll, but quite enough had been done to 
prove that the colouring matter which gives the characteristic 
brilliant green to Euglena viridis is identical chemically and 
spectroscopically with the Chlorophyll of plants. 
Some five years ago I noticed that on bringing a basin of 
tank water into a room, and placing it in a window, the 
Euglenz which the water contained collected on the side of the 
basin on which sunlight was falling, and on arranging the 
incident beams by means of the window blind, I found that 
the animals speedily moved into the direct rays, a green tint 
marking out the particular spot where the animals were con- 
eregated from the rest of the surface of the water. 
I now refer you to certain views regarding the presence of 
the green coloured bodies or granules in some of the animals 
alluded to, as well as to certain yellow bodies which are simi- 
larly found within the tissues or structures of other animals. 
