122 § 115. 
THE HELMINTIES. 
In the terminal, constricted portion of the uterus, eggs, vitelline cells, 
and spermatic particles are often found mixed together. It is probably here 
that the egos are formed, their fecundation occurring without copulation, 
and by means of the Vesicula seminalis interior. The succeeding folds of 
the uterus contain already, nicely-defined, oval eggs containing a germ and 
many vitelline cells. Their recently-formed envelope is still colorless, and so 
thin and flexible, that the peristaltic contractions of the uterus give it a 
variety of forms. But in passing from the uterus they lose this flexibility ; 
their envelope becomes more solid, — of a yellow and then a brown color ; 
and the whole, at the same time, undergoes a decrease in size, due prob- 
ably to a condensation of their substance. The eggs of most of the Trema- 
todes have an opercular opening at one extremity.“ 
Tn the Cestodes, the walls of the genital organs are so very thin, and so 
intimately blended with the parenchyma of the body, that their structure 
and relations have not yet been well made out. 
With the exception of in Caryophyllaeus,™ these organs are repeated many 
times one after another, having in the same individual different degrees of 
development. They are always most complete in the posterior portion of 
the body, being only rudimentary near the neck, while in the neck itself 
they do not exist at all. In the articulated Cestodes, each ring contains 
both male and female sexual organs; and in their two Groups, the arrange- 
ment of these is the same as in the Trematodes. It is probable that the 
ovaries and the secreting organs of the vitellus are separate.°? In Liguda, 
Triaenophorus, and Bothriocephalus, the uterus consists, exactly as in the 
Trematodes, of a very tortuous tube filled with oval eggs. 
the posterior extremity of the body. Its position 
is indicated, even when the penis is not protruded, 
by a small papilla. 
With Octobothrium, and Polystomum, there 
is around muscular sac concealed directly behind 
this opening, which contains a circle of delicate 
horny ribs, the lower extremities of which are 
bifid and form a support like a bownet. Mayer 
(Beitr. loc. cit. p. 21, Taf. IIL. fig. 3, 6) has seen 
ten similar ribs with Octobothrium lanceolatum. 
Thave found eight with Polystomum integerri- 
mum, and forty with Polystomum ocellatum. 
Their use is wholly unknown to me: 
19 The eggs of the Trematodes have apparently 
only a single envelope. Among the normal eggs in 
the uterus may often be found others which are mal- 
formed, also very irregular bodies of a yellowish or 
brown color, formed almost entirely of the. sub- 
stance of these envelopes. These bodies were 
most probably secreted by the walls of the uterus 
(the Tuba Fallopii) at a time when the ovaries and 
the secreting organs of the vitellus were inactive, 
so that the substance of the envelopes was hard- 
ened before receiving their usual contents. With 
Amphistomum subclavatum, Octobothrium lan- 
ceolatum, Polystomum integerrimum, and ocel- 
datum, and Diplozoon paradorum, the eggs are 
very large, and in the last-named species their ex- 
tremities are narrowed and lengthened into a spiral 
filament, wherefore one of these eggs has been taken 
for a testicle and penis ; see Nordmann Microgr.. 
Beitr. Hft. 1, p. 73, Taf. V. VI. fig. 1, h.; also Vogt, 
in Miller’s Arch. 1841, p. 24, Taf. II. fig. 11. 
The eggs of Monostomum verrucosum, and 
some other species of this genus which live in the 
intestine of Chelonia esculenta, have a very dif- 
*(§ 115, note 19.] See also for the structure of 
the genital organs Thaer, Muller’s Arch. 1850, 
But in 
ferent form ; they are oval and colorless, and at 
each extremity have two papillae, which are grad- 
ually developed into very long, sharp appendages 5 
see Dujardin, Hist. Nat. d. Helminth. Pl. VIII. 
fig. G, B. 3.* 
20 With Caryophyllaeus mutabilis, there is only 
a single cirrhus-sac upon the ventral surtace of the 
posterior body, and from which a delicate long 
penis often protrudes. 
211 think I have seen an ovary in each of the 
segments of Bothriocephalus punctatus, and T'ae- 
nia ocellata. As such, ought, perhaps, to be re- 
garded those organs which Eschricht (Nov. Act. 
Acad. Leop. XIX. Suppl. 2, Tab. I. fig. 2, e, e) 
has considered with Bothriocephalus latus to be 
ovaries. The organs secreting the vitellus are a 
mass of irregularly arranged granulations situated 
upon both the dorsal and the ventral surfaces, and 
which have very fine excretory ducts. This mass, 
called by Eschricht (loc. cit. p. 25, Tab. I. fig. 5) 
the ventral and dorsal granules, cannot, together 
with its excretory ducts, be made out, except when 
filled with the vitelline substance. With Taenia 
ocellata, the vitelline organs are limited to the 
sides of each segment, at the anterior border of 
which two main excretory ducts are easily seen ; 
these form a single short canal in the middle of the 
body. In this same place are two transversely- 
placed oval sacs, and which are probably the two. 
ovaries. 
22 The uterine convolutions are generally in the 
middle of the body, and when filled with mature 
eggs, appear through the skin as a brown rosette 3 
see Eschricht loc. cit. Tab. I. Il. (Bothriocepha- 
lus latus). 
p. 602, Taf. XX. fig. 17 (Polystomum appendi- 
culatum).— Ep. 
