No. 6.1 AMERICAN FROGS. 26* 



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length of the capsule itself. Sonsino finds in the case of speci- 

 mens collected in the vicinity of Pisa that the filaments are 

 from four to six times the length of the capsule. The Ameri- 

 can worms agree in this respect with those of central Europe, 

 and in no case have I found the filaments exceeding in length 

 the measurements given by the French and German observers. 

 It would seem not improbable that the greater length of these 

 filaments in the eggs of Italian specimens may be dependent 

 upon the warmer climate in which they live. 



The position of the genital pore is, as described by Looss, 

 immediately behind the pharynx, not immediately in front of 

 the ventral sucker, as is implied by the statements of Creutz- 

 burg and Sonsino. The statements of these authors differ 

 widely also concerning the presence of a penis. Sonsino 

 speaks of a " bursa del pene " lying in front of the ventral 

 sucker, and Creutzburg of a " verstulpbaren Cirrus" contained 

 in the " Samenblase." Looss writes : " In wirklichkeit ist 

 weder von einem Cirrusbeutal noch von einem Cirrus eine 

 Spur vorhanden." . My own observations are in entire agree- 

 ment with the statements of the latter author. The seminal 

 vesicle I have found in some cases filled by a mass of sperm 

 which in toto preparations or in the living animal might be 

 easily mistaken for a retracted penis. Sections show, however, 

 that the seminal vesicle is merely a simple thin-walled tube, 

 with no considerable muscular thickening or other modification 

 which can be interpreted as a penis. 



The vitellary glands are very aptly described by Creutz- 

 burg as " traubige zusammengesetzte Organe." That Looss 

 describes them as clover-leaf-shaped is doubtless due to the 

 fact that he studied them in worms so distorted by pressure as 

 to produce such an appearance. The disagreement must be 

 attributed to the " primitiv und barbarisch " method employed 

 by the latter author. The glands consist of about nine nearly 

 spherical masses clustered upon the vitellary ducts in a manner 

 very suggestive of grapes in a cluster, and the position of 

 these glands in the extreme posterior end of the body affords 

 a most simple means for recognizing the species. 



