34 THE VOYAGE OF H.M.S. CHALLENGER. 



close to those organs " die seit Cuvier fiir die Speicheldriisen gelten." For tlie rest he 

 does not say what is his own opinion in regard to the nature of these bodies. 



I do not think that since the publication of Darwin's Monograph these organs have 

 been investigated ; so I was most anxious to study them, and if possible to make out 

 their structure. They occurred in all the genera in which I sought for them ; I studied 

 them in greatest detail in the genera Lepas and Scalpellum. 



Near the place where the oesophagus communicates with the stomach, the outer surface 

 of this latter organ is invested with a pair- of oval masses ; they are placed at rather a 

 considerable distance from one another, one being found at the right, the other at the 

 left hand side of the stomach. PI. VI, fig. 7 shows their situation in Lepas anatifera when 

 seen laterally, fig. 8 when seen from the anterior (dorsal) side. In both figures (E. repre- 

 sents the oesophagus and G. S. the supracesophageal ganglion ; p. n. are the two strong 

 peduncular nerves which start from the supracesophageal ganglion ; og. is the curious eye 

 discovered by Leidy, placed close to the surface of the stomach and separated from the 

 external surface of the body by a very darkly pigmented integument and a thick layer of ' 

 muscles, which are both left out in the figures. The oviducts {pv) are also distinct in both 

 figures. They come from the peduncles and for some distance run parallel to the pedun- 

 cular nerves ; a little beyond the eye they are seen to diverge and then may be followed 

 running transversely over or at least close to the surface of the stomach. Dorsally from the 

 oviducts (in fig, 7 beneath them) the most anterior parts of the testis (t) can be distin- 

 guished. That part of the surface of the stomach which is nearest to the oesophagus is 

 covered aU over with rounded and dark-coloured tubercles {I) which cause the " disposition 

 mamelonnee" of Martin- Saint- Ange, and which when studied in a transverse section 

 appear to be the arborescent coeca of the surface of the stomach. The internal surface of 

 these coeca is darkly pigmented and this causes the blackish colour of the rounded 

 swellings at the exterior. 



The glandular bodies in figs. 7 and 8 are marked gl. They are not always the 

 same shape and size. Sometimes they are rather regularly oval and compact, having a 

 length of about 4 mm. and a breadth of not quite 2 mm. In other cases, however, finger- 

 shaped excrescences (as observed by Darwin) give the gland a much more irregular 

 appearance. In both cases the surface of the body is uneven owing to the presence 

 of globular swellings ; whilst the whole body represents an acinous gland, each of the 

 globules being a distinct acinus. 



Before giving a description of the microscopic structure of the gland in Lepas I will 

 describe its structure in Scalpellum. My best preparations are from Scalpellum paral- 

 hlogramma, Hoek. In this species the gland is relatively small, having a length of Httle 

 more than one millimetre. It is pyriform ; at the narrow extremity it communicates 

 with the interior of the stomach by means of a very narrow duct ; at the other extremity 

 ita body is rather blunt and rounded. The greatest transverse diameter of the gland in 



