PRELIMINARY NOTE ON THE LIFE HISTORY OF HYMENOLEPIS CARIOCA. By Myrna F. Jones. See allHide authors and affiliations. Science 23 Nov Hymenolepis may refer to: Hymenolepis (plant) · Hymenolepis (tapeworm) · Disambiguation icon. Disambiguation page providing links to articles with similar . 1. Science. Nov 23;68() PRELIMINARY NOTE ON THE LIFE HISTORY OF HYMENOLEPIS CARIOCA. Jones MF. PMID:
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There is a basket-like plexus of small canals figs. Within the pouch is found a further system of fibers fig. The wall of the uterus con- sists of a thin membrane fig. The sac-like rostellum fig. The broken lines are anterior to the plane of section.
Hymenolepis carioca | definition of Hymenolepis carioca by Medical dictionary
As the eggs pass out of the ovary it shrinks rapidly, and in segmentwhere all the eggs have entered the uterus, has entirely disap- peared. While the cerebral commissure connecting the main lateral nerves in T. Dorsal view of very young segments. The hymenollepis limb of the dorsal loop of the ventral vessel crosses the outgoing loop on its anterior side.
The dorsal canal fig. Transverse section through the anterior region of scolex. Some of them are apparently continuations of the other fibers br just men- tioned. As the uterus enlarges the ovary quickly disappears, and the former soon comes to occupy all the available space within the proglottis fig. There are accordingly two closed loops of the excre- tory system extending forward into the rostellum, as caripca Hymeno- lepis carioca and H.
Fibers which cross at right angles between the two strands of the commissure establish a continuity between these dorsal and ventral nerves. The length of the largest specimen was 35 mm. The vasa efferentia are wide, short tubes uniting to form the vas deferens fig. Transverse fibers are not present except a few in the pos- terior region fig. I am able to confirm Grassi’s observations, in part, as I have sections of H.
Deux nouveaux Tenias de la Poule domestique. A few dorso-ventral fibers are also found in these regions. From segment to the ovary in- creases in size very rapidly. Later he found five much smaller specimens of which he gave incomplete descriptions. The similarity between the eggs is obvious.
That the latter circumstance occurs, however, seems improbable, otherwise we should not hymenolepjs to find a specimen, as already noted, retaining hooks on the suckers, and at the same time with no trace of armature upon the rostellum. In thickness and general appearance, the wall of this narrow portion of the vas deferens resembles the membrane of the pouch, which seems to have turned in at this point to form a narrow tube through which the vas deferens passes.
The ventral canal fig.
A tape-worm which Cohn 98a considers caroica true T. The remaining few tm continue across to the other side of the segment. The outer surface of the projecting rims of the segments is marked by a number of longitudinal grooves fig.
The length ranges from 30 mm. Transverse vessels connect the ventral vessels at irregular intervals of two to seven segments, usually at an interval of about five. In the scolex they attach to the suckers, two to each. The outer layer of longitudinal muscles om consists of about one hundred muscle strands similar to the inner muscles and like them continuous from segment to segment.
Hymenolepis carioca is remarkable by reason of the small number of these bands, and their relatively large size. In fact, in many cases it can not be considered of more than specific value. In connection with each commissural ring of the pro- glottis in T.
Fibers from these nerve zones run in various directions over the surface of the suckers, and at intervals tufts are given off which extend radially toward the sur- face of the head fig. The fact alone that it has a definite and persistent uterus precludes the possibility of such a generic relationship, and furthermore its hymenolepos structural resem- blances hyymenolepis the type of Hymenolepis justify its immediate reference to that genus.
Bronn’s Klassen und Ordnungen des Thierreichs.
[1st proof of Hymenolepis carioca in Lower Austria].
A transverse muscle system is represented only by a few slender iso- lated fibers tmrestricted mostly to the extreme anterior and posterior ends of the segment, as is the case in many other forms of the genus. Since the rostellum is unarmed it would also, follow- ing Cohn’s classification, fall in caroica same subgenus Hymenolepis s.
In Hymenolepls description the number of testes is given as very few, most often three, which allows a desirable de- gree of latitude to this character. Very rarely a pore will be found on the left-hand margin.
In the regions where the zones approach one another they are connected by interlacing fibers. Cohn 99, 99a, 99b, 00a divides the genus thus characterized into two subgenera upon the cairoca of the number of hooks. VI-IX, 9 text figs. The number of segments was Near the middle of the rostellum the dorsal vessel on each side unites with the ventral vessel so that two closed loops are formed.
Fibers faintly indicating such a ring are sometimes seen fig. Consequent upon the separation of a ripe segment from the strobila, however brought about, a large area of the surface of the uterus is laid bare, and in this area a thin membrane is all that sep- arates the embryos from the outer world, facts which may play a part in their dispersal.
The form possesses three testes and in the details of cirrus pouch, the two seminal vesicles, seminal receptacle, ovary, yolk gland, and anlage of uterus shows striking similarities to H.