to grow immediately, and in course of time pieces of it were broken off
accidentally without injury to the base in the socket, which continued to
grow until 16th June 1905, when it torn out of its socket. The total
length of the feather with the pieces previously broken off, which were
measured and preserved, was 11 feet 5-1/2 inches. It therefore continued
to grow without interruption for three years and two months at an average
rate of 3.6 inches per month.

In cock A only four of the short outer rectrices were moulted in the
beginning of September 1902: the longer feathers--namely, central
rectrices and tail coverts--which ceased to grow naturally in the spring
of 1902, were not moulted till the beginning of October. This shows the
great importance of pulling out the feathers as soon as they show signs of
ceasing to grow, in order to obtain the abnormally long feathers. The
central rectrices continued to grow till the beginning of September 1903,
when that of the left side was 3 feet 6 inches long, that of the right
about an inch shorter. The coverts had ceased to grow of their own accord
some time before this, and the central ones of the posterior row were
about 3 feet long.

As it seemed possible that there was some natural congenital difference in
growth of feathers between cocks A and B, I commenced early in March 1903
to pull and stroke the feathers of the left side only in cock A, leaving
those of the right side untouched. On 30th July on the left side the
central rectrix and the first and second posterior coverts were still
growing, on the right side the central rectrix was also growing, but the
first and second posterior coverts had ceased growth and formed their
quills. The first posterior covert on the left or pulled side was 3 inches
longer than that of the right. The second posterior covert on the left
side was still longer. The first and second posterior coverts of left side