55 
means of a pipette. This fluid permeates the blood spaces all over 
the body. It differs from the blood of a hard crab in its greater 
bulk and in the increase of the amcebocyte cells of the blood, it 
also contains extraneous cells, but these appear to have been torn 
away from the delicate tissues by the pressure of the pipette. The 
blood thus appears to be prepared quantitatively and qualitatively 
for the ecdysis, after which event it will gradually lie reduced as the 
shell becomes hard. According to Cuenot the corpuscles do not 
multiply in the blood, but are produced in a rudimentary lymphatic 
gland found near the anterior extremity of the ophthalmic artery. 
This gland appears simply to consist of an aggregation of irregular 
cells from the periphery of which the amcebocytes are cut off. The 
increase of the plasma is probably largely due to osmosis. Another 
class of cells seen in the blood might be mentioned in passing 
owing to its universal occurrence. These are the explosive cells 
or thrombocytes. They are the repairing agents of the blood, 
“exploding” when movement ceases and throwing out numerous 
filaments thereby forming a network or clot over any damaged 
vessel. The thrombocytes, however, do not appear to be able to 
prevent the escape of blood from an injured limb, at all events 
when the crabs are out of the water, for unless the limb is thrown 
off' at the breaking joint, hard and soft crabs alike often apparently 
bleed to death. 
Muscuiar Tissue. — The increase of the body-fluid appears to 
be accompanied by the degeneration of some of the solid tissues. 
The muscle fibres of the claw or abdomen still possess their 
characteristic transverse striations, though not nearly so well 
marked. In the hard condition the bands are sharp and clear. In 
the soft they are dull and ill-defined, the fibre becoming semi- 
transparent having lost the opacity formerly due to its more-solid 
contents. Under a little pressure the fibres lose their definition 
and form a jelly-like mass. Sections show the fibres contracted, 
probably due to their more delicate condition, and with little 
content compared with the corresponding state in a hard specimen. 
We can thus form some conception of the manner in which masses 
of muscular tissue can be squeezed through small apertures, as it 
were in an amcebiform or worm-like manner. In this way the 
claws, the legs and the abdomen with its flattened uropods and 
toison, it can be imagined, may be easily withdrawn. 
3. Curnot : Etuilc- pliv -it)lo^i.|\ii‘s Mir ti«« < ustuoi> Decaiodi 
Archivi s tie U: >t>*ip T. xiii., 1S95. 
