96 Transactions of the 



scope, — tracing the structure of the skull in the ostrich tribe, — doing 

 a little side-business on the matter of the shoulder-girdle and breast- 

 bone, — I wasat last brought to a stand by my guide, who made me 

 solemnly promise that I would close-in upon the chick, and look at 

 nothing else until that type was worked out. I obeyed ; and being 

 already, from the influence of the Foraminifera, an evolutionist, 

 my eyes woiild see evidences for that doctrine of creation, I shall 

 not enter into details ; but I will reproduce the conclusions I came 

 to in the paper on the Fowl's Skull, in the ' Philosophical Trans- 

 actions,' for 1869, pages 803, 804. These views, thus leading to 

 evolutional doctrine, are given in the concluding remarks of the 

 recapitulation, and through the influence of my guide are, I believe, 

 clearly expressed. I wrought much with Professor Huxley in the 

 matter, who is not only clear-headed himself, but is the cause that 

 clear-headedness is in other men. My remarks are as follows : — 



" Having thus, with as much expedition and brevity as I have been 

 competent to, run through the ten arbitrary but not unnatural stages 

 in the morphological history of the fowl's head, I would conclude by 

 hinting at the importance of the various isomorjjhisms displayed by 

 the skull and face of this one type in its stages of growth. 



" I have described it upwards, but my long and really anxious 

 labour has been in the opposite direction ; the stages were traced 

 from that of the old bird downwards to that of the chick of the 

 fomth day of incubation. 



" Whilst at work I seemed to myself to have been endeavouring to 

 decipher a palimpsest, and one not erased and written upon again just 

 once, but five or six times over. 



" Having erased, as it were, the characters of the culminating 

 type — those of the gaudy Indian bird — I seemed to be amongst the 

 sombre grouse ; and then, towards incubation, the characters of the 

 sand-gi-ouse and hemipod stood out before me. Eubbing these away, 

 in my downward work the form of the tinamou looked me in the face ; 

 then the aberrant ostrich seemed to be described in large archaic cha- 

 racters ; a little while and these faded into what could just be read off 

 as pertaining to the sea-turtle ; whilst, underlying the whole, the 

 fish, in its simplest myxinoid form, could be traced in morphological 

 hieroglyphics." 



Since arriving at these conclusions I have gone still farther 

 downwards in search of morphological fact^ ; douii as to type in 

 the frog and salmon ; and down in the stages of growth, working 

 out in these fishy types the very earliest recognizable stages of the 

 skull, face, and sense-capsules. 



As to the mode in which these organisms have been worked out, 

 I may perhaps say that I have been obliged to train myself, not 

 only to be able to appreciate the whole histology of the matter, but 

 what is still more difficult, to learn the meaning of masses of tissues, 

 which form the rudiments of the various parts ; whilst, as yet, the 



