DIMENSIONS OF TJ5NIA SOLIUM. 517 



a number which in the following lengths of 25 cm. sank to 138, 76, 

 47, 33, 26, and 22, so that the total number of segments was about 848. 

 The 229 segments, after the first 414, were so distributed that 98 

 belonged to the first 5 cm., 61 to the second equal length, and 70 to 

 the remaining 10 cm. At the end of these three portions the length 

 of the joints was 0'3, 0'9, and 1/2 mm., with a breadth of 3, 3'9, and 

 5 mm. respectively. The other relations may be best seen from the 

 following summary, to which we must add that the first 25 cm. con- 

 tain not less than 414 segments : 



The 2d 25 cm. contain 1 38 joints, of which the last are 2 mm. long by 6 mm. broad. 

 3d 76 3 7'5 



4th 47 



5th 33 



6th 26 



7th 22 



5 6-5 



7'5 6 



9-8 5 



11-5 4-8 



The differences seen on comparing this table with that given 

 above 1 are trifling. They lose all importance when we take into 

 account that the number of ripe proglottides in the second worm 

 is about thirty less than in the first. Thus we see here, as in 

 Tcenia saginata, that the liberation of the ripe proglottides, apart 

 from their separation in lengths, determines many individual and 

 temporary differences. On the whole, we may credit Tcenia solium 

 with about 850 joints, which is tolerably harmonious with Kiichen- 

 meister's result, who counted 825 joints in a Tcenia 5 yards 2 inches 

 long. In this calculation a portion of the neck 6 lines long is left 

 out of account, as " unsegmented." 



The above-cited experiments (p. 496) show with considerable 

 exactness how long time must elapse before the first joints are libera- 

 ted. In the case observed by me, the patient voided the first joint 

 two months and a half after the introduction of the bladder-worms, 

 in the case observed by Yogt and Moulinie, the first joint appeared in 

 the course of the third month. On the basis of these observations 

 we may conclude that it requires an interval of from eleven to twelve 

 weeks to bring the development of the worm to completion . 2 Kuchen- 

 meister 3 agrees thoroughly with this, and notes that when he has suc- 

 ceeded in expelling the whole worm except the head, the return of the 

 proglottides may be certainly looked for in about ten or eleven weeks. 

 The various stages of progress within this period are unknown. I can 

 only note that in one case with which I was well acquainted, a tape- 



1 By an arithmetical error in the first edition of this work, the total number of joints 

 was underrated, being stated at 749. 



2 In the first edition of this work, with fewer data, I approximately estimated the 

 period at from three to three and a half months. 



3 " Parasiten," second edition, p. 90. 



