554 



many of the capillaries and smaller blood-vessels filled with organic 

 molecules, which, so far as I am able to judge from the comparison 

 of such extremely minute bodies, seem to resemble those molecules 

 which are found in the primary fasciculi. The vessels filled with 

 these molecules have their coats so thin as to be inappreciable, and 

 some of the capillaries appear to be partially destroyed, and their 

 molecular contents diffused among the sarcous elements. As this 

 is an abnormal condition of the contents of these vessels, as well as 

 of their coats, and, so far as my experience goes, is not found ex- 

 cepting in conjunction with the earliest stages of the cysticerci, I 

 am inclined to believe that the molecules in question are the same 

 as those in the primary fasciculi, and that it is by their coalescence 

 in these fasciculi that the formation-cells of the cysticerci are 

 formed. 



Addition to the foregoing communication, received 

 December 6, 1855. 



After an entozoon has left the interior of a primary fasciculus, 

 and arrived at the space between the muscular fibres, it loses its 

 ciliated investment, and begins to increase in breadth. Its 

 margin now seems to be formed entirely by the convexities of 

 the globular masses of cells of which its body appears to be made 

 up, causing it to present a crenate form similar to that of the ven- 

 tral portion of the perfect animalcule, with this difference only, 

 that these cells are compressed. The next change which is visible 

 is the formation of folds, which become more perceptible as the 

 animal increases in breadth, and which remain in the perfect 

 entozoon so long as it is confined to a small space, but dis- 

 appear when it gets to the space between the surface of a muscle 

 and the fascia covering it. The unfolding in this last situation 

 seems to be produced by the imbibition of fluid, and the consequent 

 distension of the ventral part. These more advanced stages of the 

 worm-form are best found in those specimens of diseased muscle 

 in which the perfectly developed cysticerci abound. Their number 

 in proportion to that of the perfect animalcules varies considerably 

 in different specimens. 



I have always succeeded in finding some of those of the worm- 

 form along with the perfectly developed ones ; and in some cases 



