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PROCEEDINGS OF SOCIETIES. 
Koyal Microscopical Society. 
King’s College, October 2, 1S72. 
W. Kitchen Parker, Esq., F.R.S., in the chair. 
The minutes of the last meeting were read and confirmed. 
A list of donations was read, and a vote of thanks passed to the 
respective donors. The Secretary called the attention of the meeting 
to a series of photographs of Nobert’s lines, which had been sent to 
the Society by Dr. Woodward, of the U. S. Army; the 19th band 
having been defined by Dr. Woodward with Tolies’ lens in a far better 
manner than in any previous attempts to resolve it. A note from the 
Dr., not in the room at that moment, would be printed in the Journal, 
but he (the Secretary) would just state that the lens with which such 
successful results were obtained is one that is not perfectly corrected 
for chromatic errors. Lenses more perfectly corrected did not show 
the lines so well. This was an important fact, and bore out a practice 
(of many years’ standing) by Messrs. Powell and Lealand. Their 
recent lenses, which are admirably corrected for chromatic errors, 
have been found better adapted for most microscopical work of a very 
delicate description, and yet a lens having a certain quantity of chro- 
matic error left in it produced a better photograph of the 19th band. 
Mr. Ingpen inquired whether the glass was over-corrected or 
under-corrected. 
Mr. Brooke thought it was probable that the lens was corrected 
for the rays which have the greatest luminosity, and that the darker 
ones were left to take care of themselves. 
Mr. Ingpen : If there was a slight over-correction for the blue, 
great power would be obtained in photographic work. 
The Secretary said he had received from Mr. Tegetmeier a request 
that the opinion of the Fellows should be obtained upon a pigeon’s 
feather which presented the abnormal condition of a second growth, 
or outgrowth upon an already formed feather. 
Dr. Braithwaite thought the condition of the feather resembled 
somewhat that which is seen in the vegetable world, where a con- 
tinuation of the axis of a leaf takes place, the growing point continu- 
ing itself and producing a repetition of the previous growth. 
The President concurred with Dr. Braithwaite in his opinion. 
Mr. Lowne thought the peculiarity was very much like what was 
seen in the peacock’s feather, where a similar separation of parts 
was exhibited. The condition was due to the bird being in a state of 
starvation at the time when the growth was going on. The quill 
of a feather enclosed a quantity of cellular matter which developed 
as the quill grew ; and in sickness, or when the bird was in a 
starving state, the cells died. But it was not unusual to see a fresh 
quill, as it were, growing out of the first quill. The appearance 
presented was the result of a morbid process in some degree. 
