Section IV., 1906. [239 ] Trans. R. S. C. 



XIII. — A Birch Rope; An Account of a Remarkable Tumour Growing 



upon the ivhite Birch. 



By D. P. Penhallow, D. Sc, MacDonald Professor of Botany, McGill 



University. 



(Read May 22nd, 190G.) 



\\'hile in attendance at the Forestry Convention held at Ottawa 

 during the last winter, my attention was directed to a remarkable growth 

 upon a wliite birch {Betula populifolia) , which had been found in the 

 Xew Brunswick woods and was subsequently deposited in the Mluseum 

 of the Crown Lands Department. In response to an expression of 

 opinion that the growth was of a nature which justified careful examina- 

 tion, I shortly afterward received from Mr. T. G-. Loggie of the CrowTi 

 Lands Department, a short portion of the growth which a very casual 

 examination showed to be of an extraordinary character. The informa- 

 tion accompanying the specimen was of the most meagre character, and 

 it did not afford any clue as to the causes which might have issued in 

 such an unusual development. The original, verbal information stated 

 that the growth was at least twenty feet in length, and that it hung free, 

 being attached at the upper end only. Upon comm.unicating with Mr. 

 Loggie with respect to further details, he forwarded the reply to Mr. H. 

 3i. Balkam of Plaster Kock, N.B., by whom the specimen was found, 

 which contained only a repetition of what I had heard before. It 

 therefore became evident that* any further light which might be gained 

 a.s to the cause of the growth, must be derived entirely from a micro- 

 scopical examination of the specimen itself. This examination was 

 therefore undertaken without any expectation of gaining a complete 

 solution of the question, but of obtaining such information as would 

 materially assist in explaining any similar growth should such be found 

 at a future time ; but the likelihood of a recurrence of any such growth 

 in this latitude is exceedingly remote, as it seems to have resulted from 

 a peculiar combination of circunLstances which may not again appear. 



Although the original specimen as found, is described as having been 

 some twenty feet in length, the sample which reached me was only 

 'about 36 cm long; but this was quite sufficient to establish all the essen- 

 tial features of external appearance, as well as of internal structure. lu 

 its external aspects the growth may be described aâ follows : — 



The surface is characterized by the presence of a white but very thin 

 tissue which imparts the general aspect of birch bark. This layer is the 



Sec. IV., 1906. 18 



