Mr. H. J. Carter on the Organisutiun of Infusoria. 241 



part which developes the root-like prolongations in (Edo^onium ; 

 and probably the gonidia of Ulothrix grow after the same man- 

 ner ; in which case the red body would remain in the inferior 

 half, and not be repeated, as in Euglena, when the latter fissi- 

 parates, in the still form, transversely. 



With reference to the single, glairy, capsuled body which exists 

 in the centre of Phacus, and in the large lip of Crumenula texta, 

 also dually in Euglena geniculata (Duj., spirogyra, Ehr.), one on 

 each side the nucleus (hgs. 53 a, 87 a, 88 a), 1 can state nothing 

 further than that in the two first it consists of a discoid trans- 

 parent capsule, which at an early stage appears to be filled with 

 a refractive, oily-looking matter ; that it is fixed in a particular 

 position, and remains there apparently unaltered, with the ex- 

 ception of becoming nucleated, until every part of the animalcule 

 has perished, and nothing is left but the spiral-fibre coat, and 

 perhaps a few ovules. In Euglena geniculata it is bacilliform, 

 and contains a correspondingly-shaped nucleus ; and although I 

 can state nothing respecting its uses, I cannot fail to see that it 

 has an interesting analogy, particularly in the latter instance, with 

 two similar organs, which are commonly seen in the Navicular 

 and which in A^. fulva, ex. gr. are situated in a variable position, 

 between the nucleus and the extremities on either side (fig. 89. 

 In this species they make their appearance as little specks, 

 generally previous to the development of the oil-globules, &c., 

 and, enlarging rapidly, assume a globular form, consisting of a 

 transparent capsule, enclosing a glairy, refractive, oily-looking 

 fluid. As the starch and oil-globules are developed and subside, 

 these glairy globules become distinctly nucleated, sometimes 

 irregular in form, or pedicled to the endochrome-bearing proto- 

 plasm, and, like their apparent analogues in Crumenula^ Sec, re- 

 main in the frustule when everything else has become decom- 

 posed, or has passed into minute brown-red granules (sporules ?), 

 when they present a central, glairy, circular nucleus, surrounded 

 by a double globular capsule, neither of which, like the globule 

 in Crumenula, takes any colouring from a solution of iodine. I 

 need not here go further into the description of this organ in 

 Navicula : suffice it to say, that it also appears constantly in a large 

 species of Amphiphora common in the brackish water of the 

 main-drain of Bombay, where it assumes the form, when fully 

 developed, of an elliptical body, terminated at each end by a 

 compressed, truncated, or obtuse elongation, like a barrel, and 

 is always attached to the circumference of a vesicle (fig. 90 a, a), 

 I should not have written so much about this organ here, but 

 as it is not (as, I think, is generally supposed) a common oil- 

 globule, and we know so little of the organology of the Diato- 

 mea, while its occurrence in Navicula seems to add to the other 



Ann. (S)^ Mag. N. Hist. Ser. 2. Vol. xviii. IG 



