264 Miscellaneous. 



of small canals (usually two to four), which traverse the cavity of the 

 vesicle in different directions, pierce its wall, and lose themselves 

 in the surrounding vitellus. 



In the bony fishes and Batrachia, in which there are a great number 

 of germinal spots adherent to the inner wall of the vesicle, and the 

 latter is surrounded by a system of canals radiating towards the sur- 

 face of the ovum. Each canal is connected with one of the spots. 



Multiple canals are generally met with in all ova which present 

 more or less numerous germinal spots. Sometimes, as in some Crus- 

 tacea (Crayfish, Shore-crab), these multiple spots appear also to be 

 united to each other in the interior of the vesicle by canals. 



In many Annelides, Turbellaria, MoUusca, and Acalephs the ova 

 contain only a simple germinal spot, often of considerable size, con- 

 nected with a single canal, which is enclosed in a second canal, starting 

 from the vesicle. The germinal spot also very commonly contains 

 one or more large vacuoles possessing a very manifest contractile 

 Yiower (Helix, Prostomum,Vortex, &c.). — Comptes Rendus, December 

 26, 1865, pp. 1173-1177. 



On the Lateral Canal of Lota. 

 By Professor Hyrtl. 



The lateral canal-system of this animal possesses no orifices in the 

 skin on the lateral line, but forms a closed subcutaneous tube, sup- 

 ported by cartilage throughout its whole course, and which acquires 

 a moniliform appearance in consequence of the presence of alternate 

 wider and narrower spaces. The absence of lateral orifices enables 

 us to inject this canal. By this means its cephalic ramifications are 

 also demonstrable, and these have not yet been detected in their 

 perfect connexion in any Teleostean fish. The canal reaches the 

 occipital region of the head above the suprascapula, and is there 

 connected by a wide anastomosis with that of the opposite side ; it 

 then runs above the eye to the nose, where it becomes suddenly 

 narrowed, and opens externally upon a capillary papilla in front of 

 the nasal aperture. During its course to this point it emits, behind 

 the eye, a large branch downwards ; this passes forward round the 

 orbit, emits three caecal diverticula upon the suspensorium and to 

 the articulation of the lower jaw, and terminates caecally beneath the 

 nasal pit, forming a series of ampuUiform dilatations. In front of 

 the eyes the two lateral canals are united by a short transverse duct, 

 which forms a spherical dilatation (alveus communis) in its middle, 

 and close to this emits a blind diverticulum upon the anterior frontal 

 bone. "When the canal is injected in a backward direction, we discover 

 that it has also a posterior terminal aperture, which, like the anterior 

 one, is to be seen upon a minute cutaneous papilla, about an inch 

 from the caudal fin. The canal-system of both sides of the body 

 has consequently only four cutaneous apertures. — Anzeiger derAkad. 

 der Wiss. in Wien, May 1 1, 1866, p. 119. 



