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ANIMAL PARASITES. 



Fig. 1. 



W e think that we have a certain right to judge that the pro- 

 duction of measles from the eggs of Tcenia solium is now placed 

 beyond a doubt by the experiments of Van Beneden and our- 

 selves. 



Leuckart, who has also repeated and confirmed this experi- 

 ment recognised in the mode in which Cysticercus cellulose is 

 developed from the embryo of T. solium, exactly the same type 

 as that above described as the type of the formation of the so- 

 called Cysticerci in general. It is, however, worthy of note, in 

 regard to Cyst, celluloses, that this worm acquires the vesicular 

 form, and also becomes covered with a vascular net, rather early, at 

 a time when no trace of the future head can be observed (fig. 1). 

 The first foundation of the head commences in Cyst, celluloses, 

 not before, but probably soon after the seventh week, at which 

 time the embryo is about 2'5 millim. in diameter. The first 

 trace of the head appears in the form of a lens-like thickening 

 0-07 millim., which shows itself as a white, turbid spot on the 

 clear and transparent wall of the vesicular worm, and consists of 



roundish and fusiform cells with a 

 small (0 - 0017 millim.) oval nucleus 

 and some calcareous corpuscles in 

 their vicinity The head at the 

 same time does not hang perpen- 

 dicularlv but in a diagonal direc- 

 tion from the wall of the vesicle 

 into the cavity ; it is very slender, 

 with thin walls, and in Cysticerci 

 of 3-5 millim. is about 04 millim. 

 broad and I millim. long. 



In Leuckart's experiments all 

 parts of the organism with the exception of the chambers of the 

 eye were affected with Cysticerci, and amongst others the cavities 

 of the skull, lungs, subcutaneous areolar tissue, orbits, conjunctiva, 

 optic muscles, &c. "With regard to Cyst, cellulosce in the brain 

 they were the smallest (2| — 5 millim. in longitudinal diameters, 

 in other places as much as 8 millim.), and lay in great numbers 

 (40 — 50) like the young Ccenuri free upon the surface of the 

 brain and between the convolutions in the substance of the 

 brain, in the ventricles, and between the lamella? of the dura 

 mater, forming projections from the surface of the brain and 



