254 Mr. H. J. Carter on Difflugia pyriformis. 



the great bulk of the mass is composed of the chlorophyll-cells 

 and starch-granules in nearly equal proportions. 



5. The nucleus is no longer a discoid seraiopake body at- 

 tached to the inner surface of a transparent spherical cell ; but 

 this spherical cell, which is now about the T-g-rSt part of an inch 

 in diameter, is filled (lined?) with refractive spherules, about 

 - 6 o\ o ^b of an inch in diameter, mingled with minute granules 

 and protoplasm. These contents are 7ioiv adherent to the ex- 

 ternal thick cell of the nucleus (or " nuclear utricle,^' as it has 

 been termed by Nageli), but subsequently become separated 

 from it, while in one part of the spheruliferous mass may be 

 observed a small transparent area, about TrVo^b of an inch in 

 diameter, which appears to be the nucleolus : the last is compressed 

 in shape, and will hereafter be found to form a more intimate 

 bond of union between the spheruliferous mass and nuclear 

 utricle than any other part. The spheruliferous mass seems to 

 be a thus altered state of the transparent protoplasm of the 

 nucleus, and not an increased development of the opake nucleus, 

 as I formerly thought. 



Here I would take the opportunity of correcting what now 

 appears to be an error in my description of the nucleus in 

 Amoeba princeps, viz. that whereas I have viewed the '^transpa- 

 rent area " there as caused by the nucleolus partially spreading 

 over the inner surface of the nucleus or nuclear utricle, from the 

 opposite point, and thus leaving this area, I would now regard 

 the '^ transparent area" as I have done that one which is similar 

 to it in the granulated nucleus of Diffiugia j)yriformis, viz. as 

 the nucleolus, and the opake portion as a thus altered state of 

 the transparent protoplasm of the nucleus, which ultimately 

 becomes granuliferous both in the " reproductive cells " and in 

 what I have termed the '^ granulation of the nucleus." This, 

 too, will, I think, accord better with Dr. Wallich^s figure of the 

 nucleus in his Amoeba villosa (Annals, vol. xi. pi. 9. fig. 7, 1863); 

 for I, of course, do not regard this condition now as the primi- 

 tive state and form of the nucleus, which is that probably of a 

 discoid opake body attached to the inner surface of a transparent 

 globular vesicle, as in other cells, but, on the contrary, as the 

 first phase of its generative development. Hence my assump- 

 tion that the latter state may form a specific character for A, 

 2jrinceps falls to the ground, and the villous tail, first pointed 

 out by Dr. Wallich, may prove a better indication. 



Iodine causes the nucleus of Diffiugia pyriformis, in the state 

 last described, to assume a light amber-colour, which passes 

 into a violet tint with undiluted sulphuric acid, when the whole 

 body suddenly swells up, but does not burst, the spherular 

 structure is destroyed, and the violet tint appears to be deepest 



