252 F. 0. BOWER. 



tively proved that the plastids are not newly formed in the 

 oosphereSj their relation to the organism would to a certain 

 extent remind one of a Symbiosis ; and in support of the pos- 

 sible view that the green plants may owe their origin to a 

 uniting of a colourless organism with one uniformly coloured 

 with chlorophyll, he quotes certain observations of Reinke. 

 This observer states that chlorophyll grains from a decompos- 

 ing cucumber, which were surrounded by filaments of Pleospora 

 in dead cells, continued their growth, and divided. 



From what has been above stated as to the close similarity 

 between nuclei and plastids, especially among the lower plants, 

 it seems probable that a similar view, if entertained at all, 

 ought to be extended to the nuclei; in which case the proto- 

 plasmic basis of the cell would be all that would remain as 

 representing the protoplasmic body of the host plant. Such a 

 view, however, can hardly be rationally entertained on the 

 ground of the isolated observation of a single investigator ; and 

 until it rests upon a better basis, it may reasonably be dis- 

 missed from the mind. This suggestion is, however, of further 

 interest, as it runs parallel with a similar view stoutly upheld 

 with regard to the chlorophyll bodies in certain animals, a 

 subject which was treated by Professor Lankester in the 

 ' Quarterly Journal of Microscopical Science,' for July, 1882.^ 



^ I may be allowed to briefly point out here that the recent observations on 

 the chlorophyll corpuscles of plants, so ably summarised in the above article 

 by Mr. Bower, confirm the truth of the proposition which I maintained in 

 the paper referred to, viz. that there is no more reason for regarding the 

 chlorophyll corpuscles of Spongilla or of Hydra as parasites (as Karl Brandt 

 •would do) than there is for so regarding the chlorophyll corpuscles in the leaf 

 of a buttercup. The fact which has been adduced by Haman in favour of 

 Brandt's view, viz. that the egg-cell of Hydra is " infected " with chlorophyll 

 corpuscles from its parent's tissues, is apparently no exception to what 

 occurs among green plants. There also tlie chlorophyll corpuscles are handed 

 on from parent to offspring. The parallelism of the structure of the chloro- 

 plastids of plants and animals will be obvious to any one who will compare 

 with Mr. Bower's essay my account of the chloroplastids of Spongilla and 

 Hydra, or that by Miss Sallitt in the present number of the Journal relating 

 to the chloroplastids of Stentor, Paramecium, and Euglena. 



The fact that chlorophyll does not occur even in unicellular Algae in a 



