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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Lying close against the inner surface of the shell is an ill-defined layer of flocculent substance, within which are three or four, possibly more, nuclei 2. From the region of hymenolepiw dorsal vessel where it passes behind the commissure two small canals figs. The remaining portions of the zones together correspond to the “polygonal commissure.

The vasa efferentia fig. The structural resemblance is certainly too great to allow of their separa- tion into two different subgenera, if one of the subgenera is also to contain H. The origin of the outer layer is similar to that of H.

The dorsal canal of each side finally unites with the ventral canal to form a loop right and left of the rostellum. The yolk gland yg is spherical or ovoid, 30 p. From it nervous processes an pass anteriad along the sides of the rostellum, within which, also, there is a considerable amount of nervous tissue.

The accessory lateral nerves are very small and only occasionally evident in the segments, lying a short distance dorsal and ventral from the main nerves. The main lateral nerves fig. Recherches sur la structure anatomique et histologique des Cestodes. Moreover, such genera as Monopylidium and Cotugnia, although their suckers are unarmed, resemble Davainea too much to be placed in a separate subfamily, and certainly have more in common with J 54 B.

Throughout the strobila the width of the segments is three to five times, or more, greater than their length ; the worm is thus of the type with short hykenolepis such as Hymenolepis diminuta and others of the genus. It is almost cylindrical, rarely perfectly straight, but bent more or less, usually toward the ventral surface in a gentle curve fig. The inner quadrants of the nerve zones of the nymenolepis correspond to the commissures in T.


From each of these apical branches a nerve m comes off to enter the rostellum. The outer layer fig. Four individuals of this tapeworm were collected by me, March, iooi, from the rectum of a pintail duck, Daffla acuta, shot on the Missouri river near Columbia, Mo. Hymenolepis megalops Nitzsch Was first found by Nitzsch in the intestine of Anas boschas and Dafila acuta. The protoplasm is compact and finely granular, and each cell contains a spherical nucleus 2 p.

Read more about Early Journal Content at http: The foregoing facts, I believe, furnish a very good demonstration of the untenability of Cohn’s division of the genus. Zur Systematik der Vogeltaenien, IV. In Blanchard’s description the number of testes is given as very few, hymsnolepis often three, which allows a desirable de- gree of latitude to this character. The posterior commissures fig.

Cir- cular muscles are lacking, and the membrane of the cirrus pouch fig. Branches of the excretory system apparently sim- ilar to these loops have been described by Mingazzini 99 for Hymenolepis murina. In these segments the anterior end of the uterus is more or less ex- posed.


The uterus expands forwards and outwards toward the surface, and more slowly backwards, as a simple sac without infold- ings, differing thus from Hymenolepis carioca and H. These two aggregations of fibers seem to serve the functions of retractors of the cirrus pouch and cirrus, respectively. The under surface of the rims is marked by tiny longitudinal ridges in the cuticula, folds made necessary by the decrease in area of the under surface when the rims, instead of extending laterally as in the youngest segments, come to point backward, as they do more and.


Bronn’s Klassen und Ordnungen des Thierreichs. The sac-like rostellum fig. Ventral view of posterior end of strobila. In two specimens examined the dorsal limb of the right-hand loop came from the ventral vessel, of the left-hand loop from the dorsal vessel fig. Beitrag hymrnolepis Kenntnis der Vogeltaenien. From the transverse cerebral commissure near the median line, a dorsal and a ventral pair of parallel nerves fig.

Stiles for the op- portunity of comparing with my specimens one from the U. The length ranges from 30 mm. The clear, transparent shell has a thickness somewhat over half a micron. A number of nerves extend forward from the same points.

Beyond this narrow portion the vas deferens is dilated to form hymwnolepis second seminal vesicle figs. There is still further evidence in this regard. The vasa efferentia are wide, short tubes uniting to form the vas deferens fig. Upon a priori grounds alone such a division seems exceedingly artificial, and indeed Wolffhiigel 00, 00a has demonstrated by two or three cases that it is false and misleading by reason of the non-correspondence of the superficial characters taken by Cohn to more important internal relations.

There are no diagonal fibers. From specimen in formalin. It is connected with the latter near the region of crossing cariioca two or three small vessels, and continues ventrad as the outgoing limb of the ventral loop. The latter is possibly to be identified with Taenia spicidigera Giebel I am able to confirm Grassi’s observations, hymenoleois part, as I have sections of H.

[1st proof of Hymenolepis carioca in Lower Austria].

I have also found exactly similar loops in the rostellum of H. Notes d’helminthologie bresilienne 8. Uber den Bau der Taenia infiata Rud.