bie 
272 Recent Literature, | March, 
the same manner and relative proportion as the mandibles and 
maxillæ. Here, as in other memoirs, Meinert lacks breadth and 
comprehensiveness in his treatment of arthropod morphology. 
We also think that there is a decided lack of homology between 
the mouth-parts of myriopods and hexapods, as we have en- 
deavored recently to show, the terms labium, maxillæ and mat 
dibles not being properly applicable to the myriopods, however 
alike their appendages are in the embryo to those of Hexapoda. 
Leypic’s RESEARCHES IN ANarTomY AND HıstroLocy.—Prokts- 
sor Leydig devotes the greater part of his most recent W 
“Unbersuchungen zur Anatomie und Histologie der Thiere 
(Bonn, 1883, pp. 174), to the discussion of the intimate structure 
of the tissue cells of the Insecta. A few pages treat of the tactile 
papilla of the Kentucky blind fish (Amdlyopsis spelaus), and of | 
the olfactory cones in the cray-fish from the Mammoth cave 
(Oréonectes pellucidus). As these forms have been described | 
detail in earlier volumes of this journal (Jan., '72, Dec, n 
some of the readers of the NaTuRALIST may be interested in t 
result of the distinguished histologist’s observations. | 
The tactile papilla are arranged on the top of the head 
ridges, which thus acquire a pectinated appearan beda 
Jour., 1871, PL, Figs. 7, 8, 9, 10). Professor Wyman ree , 
filament projecting out of the funnel-shaped extremity © ee 
papilla, but Leydig denies the existence of the filament, se shaped | 
that the funnel is occupied in the fresh state by a benna d 
sense-organ similar to those met with everywhere in ~ nel 8 
Teleostei, and suggests that as the thin edge of the tu ae 
occasionally prolonged into several points, one of these m . 
taken for a central filament by Wyman. ie 
In addition to the larger papillæ, isolated smaller ones a 
scattered over the head and mucous membran 
being most frequent on the lips. They are, for 
naked eye, and in fact generally require the micr oscope slightly 
demonstration. They are slender and cylindrical, with X for he 
broader base and fringed extremity, also hollowed ou 
-lodgment of a “ sense-beaker.” for bY 
As the want of sight in the blind fish is compensated ea o 
the development of the tactile ridges, so in various Cru t 
the “cave-fauna” it has been noticed that the o a 
are present to a much greater number than ID % to O% 
” 
possessed of sight. Professor Leydig was ¥ f the othe! 
pore Orconectes pellucidus in this respect with any ° ch of tt 
orth American species, but finds that the external b eT a 
antennula which bears the olfactory cones has peg of the 
ments. The cones are chiefly confined to the middle © seven 
flagellum, and are there arranged to the number punch ® 
each segment, three being on the middle and four m4 a 
my 
