578 0. A. MAC MUNN. 



stance (possibly allied to formic aldehyde) which goes to con- 

 struct proteid, by combining either with the nitrogen and 

 sulphur absorbed in the form of salts from the soil, or with the 

 nitrogenous residues of previous decompositions of proteid. 

 The starch deposited in the corpuscle is, however, the first 

 visible product of the constructive metabolism going on 

 within it ; for, unless protoplasm is being formed, no starch can 

 be produced : it may be regarded as a temporary reserve ma- 

 terial/' The fact that such " reserve material,'' while, being 

 of great service in a vegetable cell, and not being of much service 

 in an animal cell, may lead to the metabolic process stopping 

 short of its actual formation ; for it appears to me that the prin- 

 cipal use of chlorophyll in the animal cell may be to supply the 

 animal with oxygen by the decomposition of the animal's waste 

 carbon dioxide, and the formation of starch would be, to a great 

 extent, a superfluous advantage. In that case the formation 

 of starch would be more accidental than of actual necessity. 

 This view of the function of animal chlorophyll is very much 

 strengthened by the recent experiments of Regnard,^ which, if 

 confirmed, will tend to support the view that chlorophyll, even 

 separated from the '^ chlorophyll corpuscles," is of use in the 

 respiratory processes of animals. Whatever the role of the 

 intrinsic chlorophyll of the animal may be, there can be little 

 doubt as to that of the "yellow cells" of Anthea, which all 

 proofs, morphological, physiological, chemical, and spectro- 

 scopic, point out as being distinct organisms, having an in- 

 dependent life from the animal, although, of course, benefitting 

 by their position not only themselves but their host. 



If sections of the tentacles are made after hardening in 

 alcohol, it will be seen that the masses of yellow cells are 

 packed in the tentacle at random as it were, and as the water 

 is absorbed from them by the alcohol, radiating cracks appear 

 in the mass of cells which are merely laid in apposition to each 

 other, and not connected in any way as they would be if part 

 of the animal's structure. I have endeavoured to show this in 



1 ' Compt. rend.,' CI, 1293—1295, and ' Journ. Chem. Soc.,' March, 1886, 

 p. 254. 



