654 The American Naturalist. [August, 
in the study of the topography of the system and we are left absolutely 
in the dark as to the presence of ganglia in front of those of the cheli- 
cers; a point of no little importance. The eyes receive hardly more 
satisfactory treatment, owing to the unsatisfactory condition of the spec- 
imens. No vitreous body was found in the median eyes while the 
retinal cells showed no rods, and no grouping of these into a rhabdem 
was seen. The lateral eyes vary in size, shape, and arrangement and 
are described in some cases as having fused on either side of the head, 
although no evidence is presented of such fusion. The pedipalpal 
organs, reversible sacs on the tips of these appendages are described in 
detail and are clearly sensory as are the “ racquet organs” on the last 
pair of thoracic appendages. 
~~ The alimentary canal opens by the mouth at the end of the beak, 
the opening being fringed with a strainer of bristles, while the cesopha- 
gus, in front of the cesophageal collar, is modified into a “sucking 
stomach.” The midgut is provided with gland, like diverticula and 
although they are grouped into those of the cephalothorax and abdo- 
men, all clearly belong to one series, but those of the abdomen are re- 
markable not only from the number but from the fact that they empty 
into a collecting duct on either side and these ducts, in turn, empty 
into the intestines near the base of the abdomen. The Malpighian 
tubules are well developed and are described as emptying into the mid- 
gut, and Bernard accepts the views of Loman that these organs in the 
Arachnids cannot be homologous with the similarly named structures 
in the Hexapods. The heart has retained 8 pairs of ostia, while there 
are indications of another segmental chamber in front. From in front 
an aorta carries the blood forward and “ appears to discharge the blood 
directly on to the central nervous system. There are no indications of 
the circumneural vessels like those of the Scorpions and of which Mr, 
Bernard holds, in some respects, peculiar views. 
The respiratory system affords more thatis interesting. The observa- 
tions of previous students that there are three pairs of stigmata (and 
sometimes a fourth unpaired) is confirmed. Of these the first pair open 
behind the coxæ of the second pair of legs while the others compare 
with the anterior pulmonary openings of the Scorpions. Arguing 
from the conditions of the blood-vessels (and more from his preconcep- 
tions of the: phylogeny of the respiratory organs Bernard concludes 
that there were originally two other tracheal openings in the thorax. 
There then follow some interesting but inconclusive remarks upon the 
-primary number of stigmata in different Arachnids. While dealing 
with these respiratory structures the author deals with the question of 
