(Hexacoralla.)
III. CTENOPHORA.
[73] For a detailed description of the development of a single species the reader referred to Allman’s description of Laomedia flexuosa, No. 149, p. 85 et seq.
[74] Vide Ciamician, Zeit. f. wiss. Zool., Bd. XXXII. 1879.
[75] In examining the segmentation by means of sections I have failed to detect an epibolic gastrula or such irregularity as is described by Ciamician. Prof. Kleinenberg informs me that he has been equally unsuccessful.
[76] These cells are the so-called nerve-muscle cells. Their nature is discussed in the second part of this work.
[77] In the succeeding account I have followed Fol, who differs in some minor points from Metschnikoff.
[78] In my description of the development of the Siphonophora I employ Huxley’s terminology.
[79] From the expressions used by Huxley, Anatomy of Invertebrated Animals, p. 149, it appears to me possible that his opposition to Leuckart’s view is mainly as to the nature of the individual.
[80] I use this term for the group, often known as the Discophora, which includes the Pelagidæ, Rhizostomidæ, and Lucernaridæ.