QUARTERLY CHRONICLK. 167 



liisc ; and the mouth of this animal being thus deeply lodged 

 in the skin of the Echinoderm, it is clear that it can only be 

 nourished by means of the latter. This mouth, being de- 

 prived of all trace of armature, is, without doubt, destined to 

 absorb liquid or soft partg. M. Semper appears to be dis- 

 posed to consider that all the other Eulimse (equally destitute 

 of jaws) which live on Holothurise, or on other Echinoderms, 

 are nourished by the mucus secreted by the epidermis of 

 their host. 



Lastly, a very singular parasite is a little Lamellibranch, 

 which lives on the skin of a Synapta, where it is found crawl- 

 ing actively by means of a large and almost membranous 

 foot. This animal belongs to that small group of Lamelli- 

 branchs which, like certain Cephalophora, have only an 

 internal shell, or at least in which the mantle is reflected so 

 as to envelope the primitive external shell. In the species 

 in question the mantle is, it is true, completely closed, in such 

 a manner that the shell is internal in every sense of the term, 

 whilst in certain Erycinae the suture of the two halves of the 

 mantle is not complete. 



The richness of the materials of which this first volume 

 gives us knowledge makes us impatient, concludes Professor 

 Claparede, to see the appearance of those which are an- 

 nounced to succeed it. 



Max Schultze's Archiv. Vol. IV, Part II. 



I. " On the Nerves in the Tail of the Frog Larva,^'' by Dr. 

 V. Hensen. 



II. " On the Cells of the Spinal Ganglion and of the 

 Sympathetic, in the Frog,^^ by I;. G. Courvoisier. 



III. " On the Structure of the Lachrymal Glands,''^ by 

 Franz Boll. 



IV. " On the Taste-Organs of Mammals and of Man," by 

 G. Schwalbe. 



V. " On Invaginated Cells," by Dr. F. Steudener. 



VI. " 0}i the Structure, especially of the Valerian Bodies, 

 of the Beak of the Snipe," by Franz Leydig, of Tubingen. 



This number of the ' Archiv ' is remarkable for its papers 

 on nerve-structure, especially as to nerve-endings. Dr. 

 Hensen has carefully studied that favorite subject for 

 investigation in these matters, the tadpole's tail. He points 

 out and figures very beautifully the termination of nerves in 

 the epithelial cells. As the result of various researches, he 

 is led to conclude that the nerves, with the exception of the 

 sympathetic, ai'e exclusively a tissue belonging to the cor- 

 neous layer of the embryo ; that they, therefore, must end in 

 cells or cell-derivatives of the corneous laver, to which. 



