192 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
therefore, which is needed only for the act of cell-division has no further 
raison d etre in the spermatozoon, and ought consequently to be eliminated. 
After the last karyokinetic division is effected, there is to be seen in 
the cytoplasm a certain number of corpuscles which appear to be the 
remains of bodies which have, during division, been formed from the 
nuclear plasma of the mother-cell. These are the bodies which Prenant 
has called cy tomicrosomes ; as they are useless they should be eliminated, 
and for this purpose they fuse with the more or less large globules 
which form the accessory nucleus. Its fate, however, is very variable, 
in Eteone it was seen to become simply detached from the cell ; in the 
Siphonophora it persists by the side of the nucleus ; in others, as in most 
Echinoids, it forms the median segment of the spermatozoon. So that we 
may say that, when it is not expelled, it is utilized for the formation of 
one of the secondary parts of the zo<-6perm. In any case there is no 
proof that this corpuscle ought to be regarded as one of the constituent 
parts of the normal spermatozoon. 
Blood and Lymphatic Glands of Invertebrates.* — m. L. Cuenot 
deals with this subject in great detail. The following are his chief 
conclusions : — 
In almost all animals, if not in all, the blood contains a varying 
amount of dissolved albuminoid material, which, in Invertebrates, has 
ofteu both a respiratory and a nutrient function. This result was sus- 
pected by Trof. Pay Lankester in 1869. The most important, and the 
best studied, after hemoglobin, is hcemocyanin, found in Mollusca and 
Arthropoda. It is not yet known why it is in some forms replaced by 
hemoglobin, but there is some evidence that it is due to the poor oxygena- 
tion of the media occupied by the creatures that exhibit this distinction. 
The author points out the value of the coagulating power of fibrin, espe- 
pecially in those animals that are subject to fracture of their appendages ; 
its presence among Invertebrates is very variable. The Echinoidea are 
remarkable for the formation by amcebocytes of plasmodia which rapidly 
become organized and repair fractures of the test ; in Starfishes or 
Holothurians, when the body is sufficiently contractile to close accidental 
lesions, the amcebocytes only rarely form plasmodia com: arable to those 
of Sea-urchins. 
Blood-corpuscles are found in a number of Invertebrates ;~they con- 
tain an oxidizable albuminoid, always have a pretty constant form, and 
generally contain a granular stroma which may inclose colourless 
vacuoles. In any given group there are almost always exceptions to 
the rule that it possesses blood-corpuscles. 
Amcebocytes are elements of special importance, and have very 
various assimilating and nutrient functions. They almost always con- 
tain refractive granules, which are more or less abundant, and which 
the author distinguishes as alhuminogenous granules. It is believed that 
they give rise to the albuminoids dissolved in the blood-fluid. In addi- 
tion to this assimilative function they often serve as reserve-cells, in 
consequence of the accumulation of fat and albuminoids in their proto- 
plasm. They form the materials which are always ready to repair 
Arch. Zool. E.vpe'r. et Gen., is. (1S91) pp. 13-90, 365-475 593-670 (9 pis.). 
