310 J- Beard 



fello WS like it, must, in my humble opinion, be looked upon as 

 disc-forms, which may have chanced to take iip a position on the 

 side-wall of an hermaphrodite. After all my labour in searching- 

 for eggs in true dorsicolous forms^, labour, which has invariably 

 resulted in negative finds regarding the presenee of eggs, I feel 

 entitled to ask, that a positive find, because decisive if clear, should 

 be given in such a way, that there can be no doubt as to the sort 

 of specimen, to which it relates. 



From his description and figures it is abundantly evident that 

 Wheeler has uever seen the sraallest true eggs in the disc-forms, 

 as described by Prouho and myself, and as figured bere in pl. 10 

 figs. 1, 2, etc. 



He even denies their existence and origin in such places as 

 shown beyond doubt in these figures. Moreover, and this is im- 

 portant, he attaches no particular value to the position taken up by 

 a small form on the back of a large hermaphrodite, although it is 

 for the true males a very characteristic one, and is never adopted 

 by a young hermaphrodite. 



There is, and this has escaped Wheeler, a marked difference 

 in appearance in section and even in the contour of the body 2 be- 

 tween young disc-forms and true dorsicolous specimens of the same 

 size, and this is such that, once it has been recognised, it is made 

 out with ease in specimens of M. glahrum., whose seat in life was 

 unknown. As elsewhere pointed out, the cells of the dorsal Peri- 

 toneum of the males are converted into spermatozoa, whereas in the 

 hermaphrodites the cells of the same region yield mainly eggs 

 (compare figs. 5 and 13). 



Wheeler makes no reference to having met with dorsicolous 

 forms of more thau 1 mm in length. The table on pag. 295 contains 

 one, which, even when embedded, measured 1.13 mm, and among 

 myoid sections there are several-', which were certainly 1 mm and 

 upwards in length, and none of these contain any ova at all. Every 

 sectioo has been repeatedly examined, and the result has always 



1 Dorsicolous as defined on the 4ti> page of my note in tlie Z. Anzeiger 

 17. Jahrg. 1894 pag. 400. 



2 Flattened in young hermaphrodites and more convex in the dorsal region 

 in the males. 



3 The sizes of these were not noted, or the notes no longer exist, but 

 at that time (1883—84) the largest dorsicolous specimens to be found were 

 picked out, in order to test as far as possible their sexual nature. 



