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J. E. BLOOMFIELD. 
becular sustentaculum, dividing it into a number of small, 
irregular compartments, in which the true sperm cells undergo the 
changes requisite for the development of the spermatozoa, and 
accompanying these trabeculse are seen blood-vessels and capil- 
laries in section. 
If a seminal reservoir be placed directly in alcohol, so that the 
red fluid is coagulated, and sections made without staining, the 
blood-vessels will be brought out as if they had been injected ; 
and such sections will show that the blood is not confined to the 
surface, but enters into the substance of the reservoir with the 
trabeculse (fig. 4) ; in fact, the trabeculse are little more than 
networks of blood-vessels. One large vessel runs along the 
internal aspect of the reservoir, and from this main trunk are 
given off the secondary vessels which ramify over and into the 
organ. 
Development of the Spermatozoa. 
An account of the development of the spermatozoa of the 
lower animals has been for some time a want. While the ovary 
and ova have been the subject of many investigations, the testis 
and its contents seem not to have met with the attention they 
deserve; and as the earth-worm is such an easily attainable 
specimen, and its testicular products so easy of examination, it is a 
wonder that it has been so long neglected ; for if a portion of the 
contents of a seminal reservoir are examined in salt solution, a 
great many of the stages of the developing spermatozoon are 
exhibited in one field. 
The method of examination and preservation which I have 
found to answer best for the delicate ceils is to expose them in 
salt solution to the vapour of osmic acid, stain with picrocarmine 
and mount in glycerine ; and for the testes themselves and the 
seminal reservoirs I cut sections of the tenth, eleventh and 
twelfth segments, when, if all the sections are kept, the testes and 
also the reservoirs cannot fail to be found. Examination after 
treatment with osmic acid and staining reagents I have found 
more satisfactory than viewing them in the fresh state, as the 
cells are of such a delicate nature that even salt solution has a 
slight effect on them. A good method, when it was particularly 
needful to be sure that the corpuscles were perfectly unaltered, 
was to use the hsemolymph from the perivisceral cavity only, with 
the precaution that there was no confusion of the corpuscles 
peculiar to that liquid with the testicular cells. 
As each cell of the testis itself is the source of many sperma- 
tozoa it is needful to employ terms which shall distinguish the 
diflerent stages of the sperm-cells. Professor Lankester has 
