64 WILLIAM MORTON WHEELER, 



structures of a very difi'erent nature; the anterior one being obliterated 

 during the backward growth of the branchial chamber, while the 

 posterior is really the rudiment of the vein between the sinus venosus 

 and the body wall. But to use Felix' facetious expression, the 

 "Amphibienbrille" which Goette dons, is not nearly so opaque as that 

 through which Semon looked when he studied the pronephros of 

 Fetromyzon (1890), for he saw in the Cyclostome pronephros both 

 the inner and outer funnels of IcJitJii/ophis ! His figure, except where 

 it represents a single tubule provided with two funnels — which can 

 only be an anomaly, since among all the pronephroi I have examined 

 I have never seen anything like it — is a tolerably faithful represent- 

 ation of an actual section, but the statements in the text are full of 

 prepossessions derived from his previous study of Ichthyophis. Although 

 he says (p. 46) "zwar schnürt sich bei Ammocœtes (fig. 2) der dorsale, 

 den Glomerulus führende Abschnitt der Leibeshöhle nicht von der 

 übrigen Leibeshöhle ab", he adds, "aber eine gewisse Sonderung ist 

 auch hier wie ebenfalls bei Triton unverkennbar". All this statement 

 can possibly mean, as reference to Semon's figure shows, is that the 

 glomus hangs in the space between the inner surface of the pro- 

 nephric lobe and the gut, but this space is in free communication with 

 the remaining pericardial coelom, there being not the slightest trace 

 of a partition between the two. He goes on to observe that the 

 condition of the double funnels above alluded to, leads "ungezwungen 

 zu den Verhältnissen bei Ichthyophis"^ but how this can be is an 

 enigma which he does not attempt to solve. Finally he informs us 

 that the pronephric glomerulus is "bekanntlich" metameric in its 

 structure. This fact must have been too well-known to have seemed 

 worth recording in the literature, for I can find no mention of it in 

 the authors who have written on Fetromyson. I have myself taken 

 pains to record it in the present paper. 



In order that no Vertebrate, however remote from Ichthyophis 

 in the scale of being, may lack glomerular cavities cut otï from the 

 coelom and provided with both inner and outer funnels, Semon has 

 recently taken another peep through the „Amphibienbrille", and this 

 time he has singled out Myxine, a still more unfortunate object than 

 Fetromyzon, as events have proved. But it is needless to criticize 

 his work further, since the recent publications of Felix and Maas 

 must have convinced Semon himself that his general conclusions on 

 the glomerulus are quite untenable. These publications are worthy 

 of consideration because they have really clarified and advanced our 



