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sponding to the "lateraler und medialer Schenkel" of Jungersen. 

 With the inner limb the funnels communicate. 



As seen in horizontal and vertical longitudinal sections the an- 

 terior outer funnel looks forwards and outwards, and lies in front of 

 the capsule; the anterior inner funnel looks inwards and backwards, 

 and opens into the capsule near its anterior end; the posterior outer 

 funnel looks outwards and slightly backwards, and is not far removed 

 from the posterior end of the capsule ; and, lastly, the posterior inner 

 funnel looks forwards and slightly inwards, and is further forward 

 than the corresponding outer funnel, i. e. not so near the hinder end 

 of the capsule. 



Given younger stages of Amia than those at Jungersen's dis- 

 posal, it would be possible to show exactly which of the three funnels 

 of Lepidosteus persists in the former. Owing to their correspondence 

 and genetic relationship — and the latter is easy to prove — the 

 inner and the outer funnel may be spoken of as one. Interesting as 

 Jungersen's observations undoubtedly are, they unfortunately do not 

 carry us back to a sufficiently early period of the development. It is 

 not as yet known if the single funnel be or be not represented by 

 two or more at an earlier stage, and as yet the number of segments 

 over which the pronephros of Amia originally extends can only be 

 guessed at. Jungersen's services are not detracted from by the further 

 statement that similar facts regarding Acipenser are urgently called for. 

 If each one of the five inner funnels of Acipenser had a corresponding 

 outer companion in early stages, one might say of the pronephros of 

 Lepidosteus that in its first development it hints at conditions which 

 persist at a later period in Acipenser. The pronephros of the former, 

 as stated elsewhere, has an original very transient extension over five, 

 or at most six, somites. Something similar is probably true of Amia. 

 In Lepidosteus of the five or six funnels suggested in the development 

 only three actually form: these soon become difierentiated into three 

 outer and three inner ones, and later still the further reduction, pre- 

 viously recorded, takes place. From Jungersen's observations on 

 Acipenser it may be inferred with some degree of certainty, that ori- 

 ginally at least five outer funnels are laid down, that these become 

 difierentiated into five outer and five inner funnels at a very early 

 stage, and that in the first few days of the development the four 

 posterior outer funnels abort. But it appears also possible that some 

 of the inner funnels of Acipenser may owe their origin to divisions 

 of a more limited number of primary inner funnels. However this 

 may be, it is to taken as certain that at some stage of development 



