Miscellanea 
In Table C, jS, in each of Exps. 513 and 621 (not 622 as stated) one bird without crest is 
dropped. 
The climax is however reached in dealing with two matings between Birds No. 6 and 9. 
In Table C, a, Exp. 510, this is said to be a mating of DRxRR; in Table C, /3, Exp. 504, to 
be a mating of DD x RR. In the first case it is said to give four imperfect crested birds and 
none with perfect crest ; in the second case it is said to give two perfect crested birds and one 
bird without crest. In the first case No. 6 is said to have an imperfect crest and No. 9 a 
perfect crest ; in the second case No. 6 is said to have a perfect crest and No. 9 an imjJerfect 
crest. On j). 11, line 32, No. 9 is said to have a perfect crest and No. 6 an imperfect crest. 
The extraordinary versatility of these two birds is decidedly embarrassing and one is somewhat 
surprised to find that the tables in which such blunders occur are headed "Matings to Test 
Inheritance of Imperfect Crest." Davenport makes a similar blunder in dealing with two 
matings between Birds Nos. 7 and 34. It has already been pointed out that No. 7 has at one 
time no crest and at another time a perfect crest, and that No. 34 has at one time a perfect crest 
and at another time an imperfect crest. So also the mating 7 x 34 in Exp. 505 is said to be one 
of DD X DD or DD x DR, and in Exp. 513 the same mating is said to be one of DD x RR ! 
Again, Table B is divided into two sections a and /3. Section a deals with matings DDxDD 
and DDxDR, while section /3 deals with the mating DRxDR. But the distinction is purely 
arbitrary ; as has already been explained if a mating of birds with perfect crest results in one 
bird with imperfect crest, then the mating must be DRxDR but further we cannot go. The 
same criticism applies to his division of Table C into two parts. 
Various conclusions from Table III are given on p. 13, e.g. "Table III shows that when 
two imperfect crested birds are mated, the offspring have imperfect crests (Table III, A). This 
indicates that absence of occipital feathering is recessive to its presence." He gives those 
matings in Table III, A, but omits Exp. 403 which is a mating between Birds Nos. 21 and 13. 
These birds are said on p. 11 to have imperfect crests. The result of Exp. 403 is, one bird with 
crest absent and one with crest present and perfect (No. 34). It has already been pointed out 
that this bird is stated twice to have a perfect crest and once to have an imperfect crest. The 
balance of probability being in favour of its having a perfect crest, the conc-lusions drawn are 
not justified and are flatly contradicted by Davenport's own material. Further, Exp. 620 
should be deleted from Table A and placed in Table C, since Bird No. 83 has a "perfect 
crest" and not an "imperfect crest" as stated. 
Again on p. 13 we find "when both parents have a perfect crest (being therefore DD or DR) 
all the offspring have the perfect crest (Table III, B, a)." This of course would only be the 
case for the matings DD x DD or DD x DR as stated in the Table, but the heading of Table III, B 
is "Neither parent has imperfect crest" and the table actually contains an incomplete list of 
matings in which at least one parent has a perfect crest and in which one parent has (in seven 
cases out of nine) no crest at all. These statements are all consistent with each other if non- 
crested birds are considered as having jjerfect crests, but Davenport excludes them in counting 
the offspring. It is quite justifiable for Davenport to group together birds with perfect crest 
and birds with no crest since neither according to him have the bald spot on the occiput, but, if 
he does so in considering the matings, he must also do so in counting the offspring, and this he 
fails to do. He actually leaves out of account altogether 39 birds out of 112. 
It is impo-ssible to tell what he intended to include in this table ; he gives two cases of 
mating of perfect crest with perfect crest and seven cases of perfect crest with absence of crest. 
But if this is what he means, the li.st is far from complete. Assuming that his statements as 
to perfect crest, imperfect crest or absence of crest as given in Table E are correct, the following 
experiments must be added, Nos. 402, 502, 513, 604, 606, 608, 611, 701, 703, 709, and perhaps 
514 and 702. 
52—2 
