mi: <;KI:I:N MATTKK IN ANIMALS. 739 



we will therefore only notice their researches in so far as they appear to have a bearing IIJMMI 

 the origin of tlie given color of the Oyster. 



KM/' DISCOVERIES. Entz has discovered that he could cause colorless infusoria to become 

 iieen liy feeiling with green palmcllaccon.s cells, which, moreover, did not die after the death of 

 their hosts, but continued to live, growing and developing within the latter until their total evolu- 

 tion proved them to be forms of very simple microscopic green algie, such as Palmella, Qlirocyti*, 

 etc. My own observations on some green-colored infusorial animals have been of so interesting a 

 character that I will here describe what I observed in a green bell animalcule (Vorticella rhloro- 

 Klliimn). UIK>U investigating their structure, I found that next the cuticle or skin in the outer soft 

 layer of their bodies, known as the "ectosarc," at all stages there was a single stratum of green 

 corpuscles very evenly or uniformly imbedded. In another form (Stentor), as already noticed by 

 Stein, the same superficial layer of green corpuscles was observed, reminding one very forcibly of 

 the superficial layer of chlorophyl grains observed in the cells of some plants, as, for instance, 

 Amichari*. Now, it is well known that certain animalcules are at times quite colorless and at 

 others quite green; this appears to 1)6 the case with Ophrydium. In this last case I have a 

 suspicion that vegetable parasites may be the cause of the green variety, but as for the others, 

 Sh-ntor and Vorticella, I am not so sure that their green forms are so caused. In them the 

 superficial positions of the green corpuscles and their behavior toward reagents lead me to 

 think that they must be regarded as integral parts of the creatures in which they are found. 



NATURE OF THE GREEN MATTER IN ANIMALS. A grass-green planariau worm (Conroluia 

 Schultzii), found at RoscofF by Mr. Geddes, was observed by him to evolve oxygen in largo 

 amounts, like a plant, and "both chemical and histological observations showed the abundant 

 presence of starch in the green cells; and thus these planarians, and presumably, also, llt/ilm, 

 Hf)onyilla, etc., were proved to be truly vegetating animals." While some organisms, like the 

 foregoing, appear to have true chlorophyl grains imbedded superficially in their own substance, 

 others, like the radiolariaus, some siphonophores, sea anemones, and jelly-fishes, harbor true 

 vegetable parasites, or, preferably, vegetable guests. 



That the green observed in a number of animal organisms is of the nature of chlorophyl, 

 or leaf green, has been proved by Lankester by means of the spectroscope. A. W. Bennett, in 

 alluding to Lankester's observations, says: "In all cases the chlorophylloid substance agrees in 

 having a strong absorption band in the red a little to the right or left and, except in Idotea, in 

 being soluble in alcohol, and in having strong red fluorescence, and in finally losing it color when 

 dissolved." 



The vegetable organisms which have been found to inhabit the lower forms of life alluded to 

 in the foregoing paper have been regarded as belonging to two genera, which Dr. Brandt has 

 named ZouchloreUa and ZooxantheUa, and which are probably in part synonymous with the genus. 

 1'hilozoiin, afterwards proposed by Mr. Geddes. The latter gentleman, however, claims to have 

 first demonstrated the truth of the view that the yellow cells of radiolarians and polyps are alga?; 

 secondly, the foundation of the hypothesis of the lichenoid nature of the alliance between alga> 

 and animal into a theory of mutual dependence; and, thirdly, the transference of that view from 

 the region of probable speculation into that of experimental science. 



Hitherto no one has apparently noticed the occurrence of green vegetable parasites in 

 bivalve inollnsks except Professor Leidy, who has very kindly permitted me to use the facts 

 observed by him relating to Aitodan, one of our common fresh- water Mussels. In this animal ho 

 some years ago observed what must be considered to be algous parasites. He found them in 

 great numbers infesting the tissues of the Mussel and of a larger size than the nuclei of the cells of 

 the host in which they were imbedded. They were also provided with a nucleus, and were, there- 



