ART. 9 MONIEZIA, A GENTJS OF CESTODE WORMS — TAYLOR 5 



tion in the group of 15 worms wiis between no gland and 76 glands 

 to the segment. 



No attempt was made to count thQ glands in very young segments, 

 whefe they were insufficiently formed to be easily recognizable. It 

 was observed that in some worms the number of glands was smaller 

 at the anterior end, increasing toward the terminal segment; while 

 the reverse was true of other worms, and some presented a middle 

 part of the strobila with fewer glands than were seen toward the 

 two extremities. One worm showed only occasional glands in the 

 first 1,600 segments, there being only 303 glands in 777 segments 

 mature enough to show formed glands. * 



11. The position of the genital pore. According to the observa- 

 tions made, the position of the genital pore varies only with the 

 state of the muscular contraction of a segment and with the overlap 

 of the previous segment, which may cause it to appear anterior to 

 the middle but never posterior. It seems to be a very poor specific 

 character. 



12. Unfortunately no measurements were made of the eggs before 

 staining and mounting the material studied, so that it is impossible 

 to treat with these measurements as with the others. 



With reference to the M. 'planisswia type, showing the inter'- 

 proglottidal glands arranged in the form of a band, it was possible 

 to obtain only four whole worms and five portions; these were sub- 

 jected to the same kind of examination as that described for the 

 M. expansa group and gave parallel results, the specimens showing 

 great variation between segments in the same worm, and a greater, 

 but not very much greater, variation between segments from different 

 worms. 



It was not possible to find a constant relationship between any 

 of the various characters dealt with above, and the gradual series 

 of variations shown in the measurements and counts given would 

 suggest very strongly that the characters on which the determination 

 of some species of Moniezia depends are no more than individual 

 variations and have no specific value. 



Four species call for special mention. M. trigonophoj'a, as men- 

 tioned above, is distinguished by the grouping of the testes into 

 two triangular masses. This character seems to be a very variable 

 one and of seventeen specimens of the M. expansa group examined, 

 only three were found which did not possess some segments in 

 which this was shown. Two worms clearly showed the grouping in 

 every segment and twelve worms showed the two types, some seg- 

 ments with the triangular grouping, and some with the band of testes 

 running across the segment. If the number of segments showing the 

 triangular grouping are expressed as a percentage of all the segments 



