588 DE. H. CHAELTON BASTIAN ON THE ANATOMY AND PHT8I0L0GT 



extending for some distance into its substance* from and in a direction at right angles 

 to the integument, as well as a marked diiFerence in histological structure between 

 the band itself and the granular layer on which he describes it as resting. As regards 

 these latter characters I am unable to agree with Schneider. I have succeeded in 

 making remarkably thin transverse sections of these lateral bands, both when they 

 were in a moist condition (vdth a Valentin's knife) and in the dried animal. These 

 sections have been most successful both with Ascaris megalocephala and A. lumbricoides, 

 and in neither have I been able to recognize the slightest trace of any vessel in the 

 situation mentioned by Blanchard, or any natural solution of continuity corresponding 

 to what Schneider has described. Artificial cracks or fissures are, however, by no means 

 uncommon (which is scarcely to be wondered at considering the nature of the tissue in 

 question), and an examination of the figure Dr. Schneider has given, is far from dis- 

 countenancing this view of the possible explanation of what he has represented. With 

 regard to the histological structure of the lateral band, I believe this to be absolutely 

 identical with that of the deep cellulo-granular layer of the integument, and to be in 

 short nothing but an intermuscular development of it. No line of demarcation exists 

 between them, and they both consist of the same elementary constituents (Plate XXIII. 

 figs. 5 & 16), being made up of a dense aggregation of large, highly refractive parti- 

 clesf or granules, together with nucleated cells and a few interspersed fibres. These 

 lateral bands are considerably larger in A. lumbricoides than in A. megalocephala%, espe- 

 cially in the anterior parts of the body, and their structure is also denser, owing to a 

 firm fibrous network existing within them, which is most developed next the external 

 integument and extends thence inwards to the longitudinal vessel. This fibrous frame- 

 work seems to be present principally in the anterior portions of the bands, and does not 

 appear to exist at all in those of A. megalocephala. In this latter animal also the con- 

 tained vessel is not only relatively but absolutely larger than in the last-named species, 

 and may be isolated with ease. Although the arrangement of the vessels or canals in 

 these two species is identical, this can be much better made out in A. megalocephala 



• Ebeeth, I fancy, has followed Schneidek in this particular, and has given a most exa^erated representation 

 of this chink (Spalt), which figure has been introduced by Dr. Cobbou) into his recent work on " Entozoa," at 

 p. 305. I believe Eberth merely to have followed Schjteidee as regards this structure, because he does not 

 appear to have examined this Ascaris very fuljy, and I can find no mention of the structure, except in his 

 explanation of the figure. 



t These biscuit-shaped particles have often been spoken of as fat particles, but they are not soluble in a mix- 

 ture of boiling alcohol and ether, and I suspect their composition would ally them more closely to the protein 

 group of elements (MtxLEB's Archiv, 1858. Taf. xv. 2). 



J "When the inner surface of the bands of A. megalocephala is examined with a lens, it often presents a 

 sort of honeycombed or reticulated aspect for a short distance. In A. lumbrieoides, especially in the posterior 

 halves of the lateral bands, brownish-coloured patches are frequently seen at intervals, seemingly due to a 

 deposit of pigment in its substance. And in old specimens, when different portions of these cords from the posterior 

 part of the body are submitted to microscopical examination, deposits and deviations from the usual structure are 

 by no means uncommon. Schneider has represented remarkably large cellular bodies as existing in the substance 

 of the lateral bands of Ascaris acus. 



