Some Points on the General Anatoniy of Gj'rocotyle. 727 



flattened form almost without lateral ruffles represents an unduly 

 extended individual perhaps under narcotization, or eise tliat the 

 specimens obtained and stndied by otliers have been in reality badly 

 contracted and lience distorted in the other direction. 



It is, however, easily possible that both of these conditions are 

 normal under different circumstances and that in consequence the 

 reports of different observers do not clash with each other. The 

 oft quoted observations of Lönnberg on living worms support this 

 yiew and several items in my own studies on alcoholic specimens 

 confirm his position. In fact I would go further and say that the 

 lateral ruffles are not such distinct and separate regions of the body 

 as they seem to be in much contracted specimens. They represent 

 marginal extensions which are crowded with gl and follicles and 

 without highly developed muscle layers such as are found in the 

 body generally. Consequently when the main visceral region is 

 reduced to a compact mass by contraction of the powerful longi- 

 tudinal muscles, this thinner edge is thrown mechanically into folds 

 or ruffles which vary in complexity with the degree of contraction 

 of the animal and with the stage of development of the glands. 

 Facts supporting this view are readily obtained by careful ex- 

 amination of any series of specimens. 



Among the specimens at my disposal it was evident that the 

 most highly contracted individuals had the most complicated ruffles 

 (Figs. 1, 2), and that in the more extended specimens the ruffles 

 were flatter, less convoluted and in shorter folds (Figs. 3, 4). Thus 

 in one specimen the lateral rüffle measured 2 mm from the dorsal 

 to the ventral limit of the folds; the latter were few, simple, i. e., 

 not complicated by secondary convolutions, and sufficiently separated 

 from one another that it was possible to see thru between the folds, 

 the average distance between adjacent folds being nearly 1 mm. 

 In the second specimen from the identical host the dorsoventral 

 extent of the folds was between 4 and 5 mm. They projected further 

 dorsad and extended much further over the ventral surface of the 

 worm than in the first specimen. Moreover here the folds were not 

 simple but were thrown into numerous secondary folds and the 

 layers were so closely crowded together that in dorsal aspect they 

 appeared to be in immecliate contact. To this may be added the 

 Observation that in specimens placed under pressure the ruffles 

 Hatten out more or less and when the worm extends its body they 

 disappear largely or entirel}', as Lönkberg has shown. Evidently 



