Mr. H. J. Carter on Diffiugia pyriforniis. 257 



instance^ I merely mention the circumstance for what it may 

 hereafter prove worth. 



Thus^ from the granuliferous cells having been added to the 

 animal mass, and their being smaller in some specimens than in 

 others, owing apparently to an earlier stage of development, the 

 absence of tlie spherules in the nucleus while it presented an 

 effete form, and the diminution in the quantity of starch- 

 granules — to say nothing of the total disappearance of the green 

 or chlorophyll-cells, and the presence, in one instance, of a 

 capsular membrane — the colourless specimens of this Diffiugia, 

 altogether, afford strong evidence of that stage of generative 

 development in which the young brood, as yet without the 

 power of locomotion, have passed from the nucleus into the body 

 of the parent for further development. 



Since the above was written, I have examined eight more 

 colourless specimens with the same results. In four of these 

 only, however, was the nucleus seen, and in all it was more or 

 less emptied of the spherules, but not sufficiently well situated 

 for more extended examination with chemical tests. 



Of the value of the conjugation in this process it is not in 

 my power to state more than that two tests become united at 

 their apertures, and that in the pair which I found thus united 

 the chlorophyll-cells were still present, and the whole of these, 

 that is, the green matter at least, had gone over to one indivi- 

 dual ; but subsequently, part returned to their original test, and 

 a flow of contents backwards and forwards between the two tests, 

 which could be plainly witnessed under the microscope, went on 

 for a whole day after they were first discovered in conjugation ; 

 at the end of which the tests separated, and the green or chloro- 

 phyll-cells became so unequally divided, that one test only con- 

 tained one-fourth and the other the remaining three-fourths of 

 these organs, — with what amount of the rest of the contents 

 could not be seen. 



This is similar to what I have already figured and described 

 in Kuglypha (Annals, vol. xviii. p. 330, 1856), observing that, 

 ''When we find Euglypha as well as Arcella united not only in 

 pairs, but triply and quadruply in this way, and the same with 

 Euglena viridis, the connexion of these phenomena with repro- 

 duction, as Claparede has stated, becomes exceedingly doubtful.'^ 

 Now the same kind of plurality in conjugation may, and proba- 

 bly does, take place with Diffiugia pyriformis ; but, then, has it 

 no analogy with other organisms, where reproduction is evidently 

 the effect of conjugation ? Certainly in Spirogyra, wherein the 

 protoplasm becomes richly charged with chlorophyll and starch 

 just previous to conjugation, we occasionally see two cells tubu- 



