Reviews and Records in Anatomy and Physiology. 109 
Muscular System.—This was found quite developed, and it is 
a singular fact that all the muscles have a longitudinal direction. 
Transverse muscles do not exist. But Meissner has indicated a 
her describes the fibre of Mermis as readily capable of being split 
up into longitudinal fibrilla of the most regular and delicate 
character, and yet neither these fibres nor fibrille are properly 
transversely striated. He remarks however, that an appearance 
like striation is sometimes observed by a wave-like contraction of 
the fibre.+ Results of this character which the more careful re- 
search of the present day is developing, in studies of the lower 
animals especially, fully indicate that the subject of muscular tis- 
sue is not well understood as to its manifold variations of form ; 
at least, after we have left the typical forms of the higher ani- 
mals. Thus, as conrpany for the present instance, I may mention 
that Leydigt found the muscles of the alimentary canal of Arte- 
mia among the Crustacea, composed of spindle-shaped instead of 
dise-like elements, so arranged, points and bases alternating, as to 
orm a symmetrical fibrilla. In conclusion upon this system, we 
may remark that Meissner found here no sarcolemma, and no 
Perimysinm of the muscular layer. } 
_Vervous System.—The researches of this investigator in this 
direction have particular interest, because this system n 
8enerally denied to the Gordiacei, and if seen by previous observ- 
es it was only most unsatisfactory.§ But the histology of this 
system is quite as interesting. 
leissner found it so developed that he divides it into three 
Portions : a central, a peripheric, and a splanchnic portion. 
* This Jour é 
t We « Dect it inthis came egbveliie aspect that his been often ‘mistaken for 
dente” in the muscles of some of the lowest animals, thereby leading: tp no_ little 
p. 99 note, among observers in their statements. See this Journal, Jan. . 0, 1864, 
53 ee Ueber Artemia salina und Branchipus stagnalis, in Siebold and Kolli- 
@ Berthond eggs. Tat, Vit Be. Os they saw corde which might be nerves 
Beit rvati worn okelly naati ry :—for references see Siebold and 
‘us’ Comp, Anat., Amer. ed., yol. i, § 104, note 5. 
