T^NIOID CESTODES OF NORTH AMERICAN BIRDS. 19 



genital opening, filling up by a large mass of convolute spermatic canals all 

 tliat part of the articulation, and thus excluding from it the uterus. Further- 

 more, the uterus did not consist of branched, tree-like canals (see Blanchard, 

 1. c), but, on the contrary, of a large number of balls, perhaps connected with 

 each other by slender ducts. Von Siebold (1. c, p. 146, and note 23) seems to 

 speak of a similar structure observed by him or Delia Chiaje in Tcenia ocellata, 

 and Dujardiu (Histoire naturelle des helminthes, Paris, 1845) has observed 

 exactly the same structure of the uterus in a tapeworm of the European Picus 

 major. 



As in other tapeworms, the spermatozoa were very fine, filiform, of one diame- 

 ter throughout, without the so-called head or body of other spermatozoa. But 

 what was very strange, these spermatozoa were of very different lengths ; some 

 twisted, thrice or even four times as long as others. Moreover, they would 

 readily break into pieces and were not so soft and pliable as they generally are. 

 I saw several break into two pieces (particularly when coming out from the 

 cirrus bag) and both pieces moved on. Whether this phenomenon occurred 

 accidentally or whether it was a natural characteristic of these spermatozoa I 

 am at a loss to say. No water was used in the examination, of the bad effects 

 of which upon spermatozoa I am fully aware. In either case this is a subject 

 worthy the investigation of physiologists, for such a power of division would 

 imply a nature in these spermatozoa entirely different from what we have 

 hitherto observed. Other spermatozoa present individual elements ; on the con- 

 trary, those of this tapeworm would be really dividual, at least virtually, as 

 they have the faculty of dividing and thus multiplying themselves. Not the 

 slightest difference could be observed in activity, movement, or form between 

 the divided portions and the whole animals, so that we may suppose that each 

 of the divided pieces had the fructifying power as \\q\\ as the others. Further- 

 more, the motion of these spermatozoa was extraordinary. Whilst others move 

 in a peculiar, quick, vibratory manner, these progress much more slowly in a 

 succession of long curves, reminding one of the motion of an eel at the bottom 

 of a river. 



This same tapeworm is also remarkable for the strange shape of its eggs. 

 While the eggs of tapeworms generally are globular or oval, the shape of these 

 was that of a large ball running out on both sides into tubes which terminated 

 in balls of about half the diameter of the central one. 1 found these eggs in 

 all stages of development, some containing nothing but a clear yolk, while others 

 presented embryos with six little spines. The yolk as well as the embryo was 

 found only in the central ball, and there also the yolk membrane terminated. 

 Thus the lateral tubes of the egg, as well as the balls in which they terminated, 

 are to be considered merely as excrescences and appendages of the outer (the 

 third) coating of the egg. Similar appendages to the eggs of tapeworms have 

 been met with previously by other observers, namely, threads running out on 

 two sides in Tcenia infundibuUformis and planiceps, by von Siebold (1. c, p. 148), 

 and Tcenia eyathiformis, by Dujardin (1. c, p. 568, and figured pi. 9, fig. R., 2), 

 while von Siebold (1. c. ) describes the eggs of the same worm as provided at 

 the pointed ends of their outer pear-shaped coatings with two bladder-like 

 appendages, which remind one more of the new form just described. Two 

 delicate tufts, one on each side, have been observed by Meissner in Mermis 

 nigrescens (Beitrtege zur Anatomie und Physiologie der Gordiaceen, in von 

 Siebold and Kolliker's Zeitschrift f. Wissensch. Zool., vol. 7, pi. 2, fig. 2), and 

 by Siebold (1. c.) in Tcenia variabilis. All these appendages belong to the third 

 coating of the egg, adjoining the so-called chorion. Analogous ai>pendages 



