388 ; Miscellaneous. 
old women remained day and night, all the ceilings and windows, 
which were white-washed, were entirely covered with a green mouldy 
coat of Penicillium glaucum, whilst all the walls, which were 
painted in oil, were completely lined with a black and white mould, 
which presented the same A. nigricans as the patient’s ear, only under 
the form of Achorion (according to Hallier). But a single cultiva- 
tion in glycerine or on lemon sufficed to change it into a plant with 
well-developed sporanges....... Washing the walls and ceilings 
with a solution of hypochlorite of lime, which was also employed in 
the ear, and the establishment of good ventilation, speedily put an 
end to the sufferings of the patient, upon whom all my therapeutical 
resources had previously failed.—Comptes Rendus, August 26, 
1867, pp. 368-371. 
The Theory of the Skeleton. 
To the Editors of the Annals and Magazime of Natural History. 
GENTLEMEN,—Absence from town has prevented me from seeing 
the ‘ Annals of Natural History’ since July. | 
I have but a few words to say in reply to Mr. Seeley’s letter in 
your August Number. 
Any one who chooses to be at the trouble of reading the two 
pages in the ‘ Medico-Chirurgical Review,’ from which Mr. Seeley 
extracts seven lines, will find as definite an outline of the theory of 
mechanical genesis of vertebree as could be put in the short space 
available. 
If he is at the further trouble of referring to the ‘ Principles of 
Biology,’ §§ 254-258, he will find what Mr. Seeley chooses to call 
‘“‘vacue hypothesis.” Where Mr. Seeley ‘did not notice that 
these ‘incident forces’ (producing vertebral structure) were de- 
fined,’ he will see specified and illustrated by diagrams the par- 
ticular incident forces which produce differentiation of the vertebrate 
axis from surrounding tissues, the particular incident forces which 
cause segmentation of it, and the particular incident forces which. 
cause ossification to commence at the places where it does com- 
mence. 
If, once more, he turns to § 301 (which I suppose Mr. Seeley 
overlooked), he will find definitely specified the particular physio- 
logical actions through which pressures and tensions cause the 
formation of bone. 
Here, so far as I am concerned, the controversy must end. 
I remain, Gentlemen, 
Yours, &c., 
HerBerT SPENCER. 
