HELMINTHES. 
607 
Cysticercus cellulosae. Hessling appears to have anticipated 
Rainey in the dis'covery of these bodies, having found them in 
the heart of the sheep, ox, and roe (Siebold and Kolliker^s 
Zeitschrift, Bd. v. S. 196, 1853). Leuckart regards them 
as sacs of Psorospermiae. The formation of the receptaculum 
capitis and its contents are minutely described ; also the deve- 
lopment of the sexual organs of the mature Tcsnia solium and 
its contained eggs. In like manner the Tania mediocanellata 
in all its life-stages is carefully considered— its specific charac- 
ters, tendency to become monstrous, structure, development, 
and clinical importance being especially dwelt upon. Of the 
highest interest is LeuckarPs account of the rearing of the 
measles of this species in the calf. He records three experi- 
ments- — two in the body of the work and one in an appendix. 
The first experimental animal died, but the second recovered. 
In both instances a violent kind of leprosy followed the admi- 
nistration of the proglottides of Tania mediocanellata, owing to 
the migration of the six-hooked brood in extraordinary num- 
bers. He proposes to call this malady the acute cestode 
tuberculosis.^^ The third experiment seems, more properly, to 
belong to Hosier, and will be referred to below. In this in- 
stance the animal also perished. In any case, Leuckart has the 
chief merit in this connexion, and one cannot help admiring 
the very praiseworthy manner in which he is always careful to 
award to prior investigators their legitimate due. It is well 
known that Kuchenmeister in the first instance, follqwed by 
Huber of Memmingen, and Schmidt of Frankfort, had pre- 
viously hazarded correct opinions as to the true source of this 
tapeworm. 
It must also be noted that our author gives very cogent 
reasons for rejecting KiichenmeistePs opinion respecting the 
existence of separate kinds of Echinococcus-larvae. The Echino- 
coccus scolecipariens and altricipariens are only modified forms 
of the same animal, the alleged differences as to size, character, 
and proportionate number of the cephalic hooks having refer- 
ence merely to the degree of development of the particular spe- 
cimens under observation. Leuckart confirms the previous in- 
vestigations of Von Siebold, Haubner, and Kuchenmeister as 
to the true source of these larvae, and finds that the sexually 
mature tapeworm, or Tania echinococcus, requires a period of 
seven weeks for its development from the scoleX condition. He 
enters most minutely into the subject of hydatid-formation, and 
discusses fully the so-called exogenous, endogenous, and multi- 
locular varieties ; but perhaps the most interesting observations 
in this relation are those which specially refer to the separate 
Echinococcus-heads, the brood-capsules in which they are con- 
tained, and particularly also the phenomena of proliferation. All 
these differentiations are modified buds which proceed from the 
