60 SUMMARY OF CURRENT RESEARCHES RELATING TO 



rightly placed on the dorsal surface of the foot, but in fig. 2 they are 

 palpably attached to the ventral surface. 



A similar confusion is to be seen in the drawing of the last new 

 species, Botifer elongatus ; for in pi. xxxi. fig. 2 the dorsal antenna and 

 the proboscis ("trompe") are actually drawn on opposing surfaces; the 

 proboscis being placed on the ventral surface, beneath the buccal orifice. 



Space would fail us to point out the numerous errors contained in 

 M. Weber's off-hand corrections of the observations of others; but two 

 of these deserve notice. First, M. Weber states that the male Rotifera 

 have no contractile vesicle (" cette vessie n'existe pas chez le male";) and 

 that the lateral canals open directly outwards on each side of the penis. 

 Now, nothing can excuse so gross an error. If M. Weber had ever 

 examined a male Asplanchna (a common animal enough), he would have 

 seen in it a contractile vesicle that no beginner could miss. He would 

 have seen it contract, and he might have counted, even, the muscular 

 threads to which the contraction is due. The very memoirs he quotes 

 from, and of which he gives a list, ought to have preserved him from 

 such a blunder ; were it not that M. Weber appears to have no doubt 

 that, when an observer differs from him, the person in error cannot be 

 himself. 



The following is an amusing instance of this curious belief in his 

 own infallibility. M. Weber fails to find the contractile vesicle in the 

 male of Hydatina senta, so he dismisses all the observers who have seen 

 it by saying, " Cohn, Leydig, Daday, and Hudson have seen it with the 

 eye of faith I " 



Again, when describing the trophi of BracMonus urceolaris, he chal- 

 lenges the accuracy of Gosse's beautiful figure in his famous memoir 

 " On the manducatory organs," and offers one of his own as more correct. 

 It is well worth while to place these figures side by side ; and at the 

 same time to look at M. Weber's figure of the trophi of Hydatina senta. 

 The comparison will give a very fair measure both of M. Weber's 

 capacity and of his own opinion of it. 



We have only space to notice one more extraordinary statement. 

 M. Weber, when describing the rotatory organ of the Eotifera, says that 

 it consists generally of two ciliary wreaths : one (for locomotion) which 

 is always in movement ; and the other (for bringing nourishment to the 

 mouth), which moves or not, according to the animal's pleasure. He 

 further says that in the Ehizota this latter wreath "is usually very 

 reduced, and forms a semicircle round the mouth." Can M. Weber ever 

 have seen Melicerta ringens 9 and if he has, can he have failed to see 

 that the secondary wreath, which brings food to the buccal orifice, is 

 not a mere semicircle round the mouth ; but that it runs almost entirely 

 round the trochal disc, parallel to the greater wreath, and of length 

 quite equal to it ? Of course, these remarks apply equally well to a 

 Limnias, CEcistes, Conochilus, Lacinularia or Megalotrocha ; yet M. Weber 

 studies a new species both of CEcistes and Limnias, and misses altogether 

 the real structure of their Ehizotic coronae. 



Parasitic Rotifer — Discopus Synaptse.* — Dr. C. Zelinka gives a 

 detailed account of this parasitic rotifer, to the preliminary notice on 

 which we have already called attention.f The following notes may be 



* Zeitschr. f. Wiss. Zool., xlvii. (1888) pp. 333-458 (5 pis.). 

 t This Journal, 1888, p. 52. 



