ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
603 
the changes in the digestive cells and of the modifications seen in the 
ingested blood. The excretion of the Malpighian tubules, at first 
liquid, takes the form of extra-cellular sphero-crystals. As these were 
often found in the integument of Ixodes in a state of repletion, it seems 
as if the waste-products do not always follow the normal path of elimi- 
nation. Batelli then describes the respiratory system. The stigmata 
are thoroughly integumentary in origin, and morphologically comparable 
to clusters of hairs. Of a dermatoptic sense in Ixodes no experimental 
evidence was to be had, but'the author discusses the structure and very 
dubious physiological import of tarsal and other organs which seem as 
if they were sensory. 
Development of Limulus longispina.* — Mr. Kamakichi Kishinouye 
has investigated the development of this King-Crab. The epiblast is 
developed in two ways ; that of the ventral surface arises from the 
superficial layer of cells of the blastodermic thickening, while that of 
the dorsal surface is ditferentiated from the immediately underlying hypo- 
blast cells by rapid multiplication. The mesoblast has three sources, 
one portion arises from the cells which form the lower part of the 
blastodermic thickening, and forms the mesoblast of the cephalothorax ; 
the second portion arises from the primitive streak, and forms the meso- 
blast of the abdomen ; the third portion arises from certain yolk-cells, 
and its fate is uncertain, but it probably becomes differentiated into 
blood-cells. The cephalothorax, which consists of the cephalic lobe 
and seven succeeding segments, forms the greater part of the egg, and 
becomes gradually flattened by the horizontal increase of the ventral 
plate. The abdomen is not developed till very late, and it is remarkable 
for having yolk in the middle portion only. 
The lateral halves of the nervous system develope independently of 
each other ; at one time the nervous system consists of peculiar groups 
of cells which resemble the ommatidia of the eye. They disappear 
when the ventral nerve-cord is divided into ganglia and begins to be 
separated from the epiblast. Two pairs of shallow cephalic invagina- 
tions appear, but disappear before the nervous system is separated from 
the epiblast. The brain of Limulus may be divided into four parts, the 
ganglion of the median eyes, the ganglion of the lateral, and the anterior 
and posterior portions of the brain proper. The lateral compound eye 
of Limulus is at first an epiblastic thickening with an invagination like 
a simple eye, and not a group of thickenings or invaginations. The 
lateral eyes are not thoracic but cephalic, and they shift their position 
gradually. The median eye of Limulus appears as a thickening anterior 
to the brain, and outside the semicircular cephalic groove, while that 
of the Arachnida appears as a thickening at the posterior end of the 
semicircular cephalic groove. 
The coxal gland, which is probably a degenerated excretory organ, 
is not exactly homologous with that of the Spider. In the latter 
the gland opens at the base of the third appendage, and reaches to 
near the base of the sixth appendage, while in Limulus the gland opens 
at the base of the fifth appendage, and developes forwards to the base 
of the third. 
* Journal Coll. Sci. Imp. Univ. Japan, v. (1892) pp. 53-100 (7 pis.). 
