18 MR. W. YARRELL ON THE LAWS WHICH APPEAR TO INFLUENCE 
ruff and head feathers appeared almost immediately, and were perfected by the 4th of 
May. This bird began to shed his ruff feathers on the 8th of June, and by the 6th of 
July he had lost them all. 
The feathers that formed the ruff round the neck of this same bird in the spring of 
1831 were ash-coloured ; but the feathers that ornamented the same part during the 
spring of 1832 were decidedly black. 
Manpvarin Ducx.—Anas galericulata, Linn. 
The male bird commenced moulting off his breeding plumage about the 24th of May, 
and by the 3rd of July he so much resembled the female in the colour of his plumage, 
that it was a matter of some difficulty to distinguish them unless by a close in- 
spection. He remained in this state until the 22nd of August, when he began to shed 
the feathers which were to be replaced by others of a more brilliant colour, and on the 
25th of September he appeared in his perfect breeding plumage. In this last moulting 
the bird did not shed all his feathers, as in the spring,—but only those that gave place 
to new ones of a more brilliant colour. The wing and tail primaries, and the plainer 
feathers, were those produced in spring. 
Summer Ducx.—<Anas Sponsa, Linn. Dendronessa Sponsa, Swainson. 
The male of this species began to moult off his breeding plumage about the 14th of 
June, and by the 29th of July his feathers differed but little in colour from those of the 
female. He remained in this state until the 24th of August, when he began to shed 
those feathers whose places were to be occupied by others of a more brilliant colour, 
and on the 27th of September he was in full plumage. The wing and tail primaries, 
and some plain feathers, remained as in spring. A brood of Summer Ducks was hatched 
on the 17th of July, and by the 18th of September the young birds had completed their 
first feathers. They then commenced a partial moulting, and by the 14th of November 
were in as perfect a state of plumage as the parent birds. 
Cormorant.—Carbo Cormoranus, Meyer. 
Some white feathers on the side of the head and neck began to appear on the 4th of 
January 1832, and arrived at their greatest perfection by the 26th of February. They 
remained in this state till the 2nd of April, when they began gradually to disappear, 
and by the 12th of May were wholly lost, having been fifty three days arriving at per- 
fection, thirty six days stationary, and forty days disappearing,—making together a 
period of eighteen weeks three days. These feathers are new ones, much longer than 
the black feathers of the same part, rounded in form, and in some degree resembling 
bristles. Some white feathers began to appear on the thighs of the same bird on the 
25th of January, and the patch was completed in five weeks. These white feathers 
began to disappear about the 16th of June, and by the 20th of July were almost en- 
tirely gone. A young Cormorant brought to the Garden in the summer of 1830, did 
not go through any change during the summer of 1832. 
