236 Miscellaneous. 
appearances, due probably to compression, and that they have not 
seen the true arrangement of the peripheral nervous system of these 
little creatures. As this arrangement is really very remarkable, I 
shall now give a short description of it. 
Beneath the cuticle, which is smooth or striated, but always 
structureless, we find a very thin and very refractive granular 
layer. This layer has neither been figured nor described by M. 
Marion; but Dr. Charlton Bastian*, in 1866, indicated it very 
clearly, and even recognized that it contained cells. To investigate 
it properly it is necessary to macerate entire worms in a mixture 
of acetic acid, alcohol, glycerine, and water—a mixture which has 
already rendered me great service in many cases, and the formula 
of which I have given in my ‘Monographie des Dragonneaux.’ 
The marine Nematoids, when immersed in this liquid, quickly be- 
came perfectly transparent. We can then see very distinctly that 
the granular layer situated between the skin and the muscles con- 
sists in great part of very fine fatty granules, and that it contains, 
scattered through it, small stellate cells furnished with a very re- 
fractive nucleus. 
The relations of these little cellular bodies to the sete or papillae 
are easily ascertained. In a longitudinal section we perceive very 
distinctly that from the apex of each cell, perpendicularly to the axis 
of the animal, issues a very delicate thread which, after having tra- 
versed the whole thickness of the cuticle, arrives at the base of the 
papilla and enters it ; but each cell also furnishes laterally a certain 
number of processes which place it in relation with the neighbouring 
cells ; and it is equally easy to ascertain this, if, instead of making a 
section of the animal, we endeavour to follow the granular layer 
over a certain portion of its surface, by gradually raising the object- 
glass of the microscope. The subcutaneous layer of the marine 
Nematoids, therefore, contains a true network of ganglionic cells, 
which furnish nervous threads both to the organs of touch and to 
the organs of vision. This peripheral network is in relation with the 
central nervous system by means of a plexus, which traverses the 
muscular layer and unites the ventral nerve with the subcutaneous 
layer. 
These are undoubtedly facts of detail and of delicate observation ; 
but still they are of importance, for they are not isolated. It will 
suffice for me to recall that various observers have indicated a very 
analogous network in the Actiniz, and that I have myself described 
one exactly similar in Gordius. This network arrangement of the 
ganglionic cells is certainly less rare in the Invertebrata than has 
hitherto been supposed; and it is probable that it represents in 
itself the whole of the nervous system of inferior types.—Comptes 
Rendus, February 8, 1875, p. 400. 
* “On the Anatomy and Physiology of the Nematoids, parasitic and 
free,” Phil. Trans. 1866, vol. clvi. part 2, pl. xxviii. fig. 36, d. 
