HOUWINK’S EXPER. CONC. THE ORIGIN OF SOME DOMESTIC ANIMALS. 153 
CHARTER: TT. 
THE MATERIAL AT HAND 
During the first years of the experiments all birds which died were 
stuffed at Mr. HouwInk’s expense and the skins preserved in his col- 
lection. Later the Director of the Rijks Museum van Natuurlijke Historie 
at Leiden, Professor E. D. van OoRT kindly consented to have the ani- 
mals which died, mounted at the expense of the Museum and to have 
them stored there. 
Various circumstances, unsuitable storage of Mr. HouwINnx’s collec- 
tion,after the breaking up of his establishment,misunderstood directions 
etc. have caused the loss of skins, or, equally serious, that of labels or 
rings, so that the collection is by no means complete. 
Fortunately Mr. Houwrnx’s first scientific assistant, Dr. H. N. 
Koorman had made feather-charts of a number of the birds when suill 
alive, and these, though incomplete, have been of great use, as also some 
coloured drawings and a large number of photographs made at the ex- 
pense of the Dutch Society for the Promotion of Scientific Breeding. 
The latter however have suffered by the impossibility to photograph 
the contrast between certain browns and black, both of which make 
the same impression on each and every kind of photographic plate 
tried. All our efforts to photograph black and brown mottled breasts 
have been completely frustrated by this untoward circumstance. 
The following material, and notes pertaining to it, were at the dispo- 
sal of the senior author while writing up the results obtained by Mr. 
HOUWINK. 
In the first column a + indicates that the animal died. 
A? behind the registration-number of the bird means that the sex of 
the animal has remained unknown. 
In the second column particulars as to photo’s, drawings and stuffed 
specimens, in the third such as to feather charts are given, while the 
fourth indicates which specimens were sent in December 1921 to Mr. 
LEURING at Mook, and which of these were still alive at the beginning 
of March 1923. 
When a column has not been filled in, it means that no particular, 
pertaining to that column, could be ascertained ; when no column, ex- 
cept the first, is filled in, that the fate of the animal subsequent to birth 
has remained unknown. 
