180 EDWARD B. POULTON. 
9. Mavrer.—(a) “ Hautsinnesorgane, Feder- und Haare-anlage,” ‘Morph. 
Jahrb.,’ xviii, 1892. 
10. Mavrer.—(d) “ Zur Phylogenie der Saugethierehaare,” ibid., xx, 1893, 
p. 260. 
11. Mavrer.—(c) “ Zur Frage von d. Beziehungen d. Haare d. Saugethiere,” 
ibid., p. 429. 
12. Romer.—“ Ueber d. Bau und Entwick. d. Panzers d. Giirtelthiere,”’ 
‘Jen. Zeit.,’ xxvii, 1892. 
13. WrBer.—(a) “Beit. z. Anat. und Entwick. d. Genus Manis,” ‘ Zool. 
Ergebnisse einer Reisen in Niederl. Ostind., 1892. 
14. Wesrr.—(4) “ Bemerkungen tiber d. Ursprung d. Haare und iiber 
Schuppen bei Saugetieren,” ‘Anat. Anzeig.,’ viii, 1893, p. 413; and 
translated in ‘ Annals and Mag. Nat. Hist.,’ July, 1893. 
15. Emery.— Ueber die Verhaltnisse d.Saugethierehaare zu Schuppenartigen 
Hautgebilden,” ‘ Anat. Anz.,’ vill, 18938, p. 731. 
2. Conclusions derived from the Study of 
Ornithorhynchus. 
Referring to the interesting historical account written by Dr. 
Benham, I will first endeavour to give reasons which seem to me 
to oppose Gegenbaur’s and Kolliker’s distinction between hairs 
on the one hand and feathers and scales on the other, founded 
on the fact that the former are developed from the base of a solid 
epithelial downgrowth, the latter from an epithelial upgrowth. 
I have never regarded this distinction as a very important 
one, and I believe that it may be successfully opposed even if 
we had not the arguments which follow from the condition 
here shown to obtain in Ornithorhynchus. The papilla and 
epidermic bulb forming the hair are clearly parallel to the 
papilla and epidermic cells over it forming the feather and 
‘scale, the one projecting upwards at the bottom of a solid 
downgrowth, the other projecting upwards from the free 
surface. The only morphological distinction worthy of con- 
sideration is the fact that the downgrowth is solid. But even 
this difference is, in all probability, to be explained as a simple 
result of the formation of follicle first and hair afterwards 
as contrasted with feather first and follicle afterwards, while the 
reversal of order is not in itself at all difficult to understand, 
