186 
As a contrast to the schema of the origin of various Vertebrates, 
promulgated by RAgBL ') in the form of,an ancestral tree — in which the 
assumed loss and gain of food-yolk is graphically expressed — I will 
also subjoin a plan, more like a shrub than a tree, of the relation- 
ships of the Ichthyopsida as they at present appear to me. I will only 
remark that the ancestry is far less certain than the relationships. 
In the first place: Amphioxus nowhere; a weed which has crept 
in the Vertebrate garden. 
Teleostei Amphibia Dipnoi 
(meroblastie) (holohlastie) (probably holoblastie) 
V ET - 
Marsipobranchii Ganoidei Selachii Protodipnoi 
(holoblastic) (meroblastic) (holoblastie) 
ne aA N | ye 
ne ve V y \ 
7 
Protoganoidei Protoselachii 
(more food-yolk, total segmentation, supra-renals 
absent entirely on this side) 
N 
(total segmentation) 
wa 
4 
Protovertebrata 
(little food-yolk 2), total segmentation) 
It would doubtless be interesting to find some traces of suprarenal 
bodies in the Dipnoi; for then we should have once again a com- 
plete contrast between the two divisions of the Ichthyopsida. Supra- 
renals appear to be absent in the Dipnoi. PARKER describes none, 
and my own results were negative as to the presence of such struc- 
tures. Their absence, if it be a fact, shows however that the Proto- 
selachii and Protodipnoi did not yet possess them >). 
1) Rast, C., Theorie des Mesoderms. Morph. Jahrb. Bd. XV, p. 157: 
2) Like Rast I denote increase of food-yolk by the algebraical sign 
<, but dispense entirely with the sign of decrease ! 
3) Brpper’s organ of Toads appears to me to be a true supra-renal body. 
