1831 UPE HISTORY OF GORDIUS AND PARAGORDIUS—MA 7 63 



bristles in Gordius robustus may be homologous with the protoplasmic 

 strands in Paragordius varius, but they do not appear to retain living sub- 

 stance in the adult condition. 



Montgomery states that he failed to find any strands of protoplasm 

 passing thru the fibrous cuticula of Paragordius varius but found granules 

 in the fibrous cuticula of the male in the region where the tubercles are 

 present. He also figures branching roots for the tubercles. His method of 

 staining for a long time with iron hematoxylin would not readily bring out 

 continuous fibers. What he figures as granules in the fibrous cuticula are 

 undoubtedly nothing more than the ends of some of the protoplasmic 

 strands which in that locality are very large. The roots of the tubercles 

 can be nothing else than several pieces of strands which he could not trace 

 accurately and consequently regarded as passing to the same tubercle. 

 The protoplasmic strands in the cuticula have been figured for other species 

 of Gordiacea, and Vejdovsky (1894) shows them in definite relation to the 

 areolae. 



Hypoderm and nervous system. It is impossible within the space of this 

 paper to discuss the minor differences that exist in the descriptions of the 

 h)rpoderm. Some of the artifacts in the figures of Vejdovsky have already 

 been pointed out. 



The development of the nervous system requires no further discussion. 

 In the structure of the nerve cord a minor difference appears in the two 

 species studied, in Gordius robustus the neural lamella consists of a series 

 of cells while in Paragordius varius all the cells are located in the cord it- 

 self and only fibers connect the cord with the hypoderm. The subneural 

 canal of Vejdovsky was probably an artifact due to the separation of the 

 hypoderm cells at the point where the fibers from the cord enter. Rauther 

 regarded most of the large cells of the nervous system as belonging to the 

 supporting tissue. That is certainly an error. 



The mass of cells in Paragordius varius designated by Montgomery as 

 retina must be regarded as the major part of the cephalic gangHon. 



Alimentary canal. The favorite textbook doctrine that the alimen- 

 tary canal of the Gordiacea is well developed and functional in the parasitic 

 stages must be regarded as disproved. Vejdovsky has already pointed out 

 that there is no difference in the essential structure of the alimentary canal 

 in the young forms and in the adults. He, however, was unable to trace 

 the origin of the anterior part of the tract, as the youngest specimens 

 examined by him were at the stage where the adult cuticula begins its 

 formation and were in such miserable state of preservation that he was 

 unable to locate the gonads in them. Evidently the entire interior had 

 become disintegrated. He found the larval proboscis at the point where 

 the mouth should have been, but in spite of that regarded the mouth as 

 open. In his forms the larval esophagus underwent even more development 



