332 



being much narrower in proportion, and the margin being altogether more bluntly cut 

 or divided. I am inclined to believe from the consideration of these several forms that 

 either the number of our native species of oak is at present undetermined, or that in 

 reality we possess but one.^Joseph Sidehotham ; 26, York St., Manchester, August 12, 

 1842. 



211. On Monotropa Hypopitys. In deference to such high authority as that by 

 which Mr. Newman's views are supported, I have re-examined the subject with much 

 care, and specimens kindly supplied by Mr. Newman in a recent state have been stu- 

 died in connexion with others obtained from Southport. Before I state the conclu- 

 sion at which I have arrived, let me acknowledge to my much-esteemed opponents, 

 that although I consider them to have been mistaken, I regard their error as scarcely 

 to be avoided under the circumstances. I have seen a portion of a specimen corre- 

 sponding with that which they examined, and was myself strongly inclined at the first 

 to coincide in their view ; nor was it until after very minute dissection that I perceived 

 any fallacy. The " rhizoma " had apparently an uniform fibrous covering; but in the 

 specimen since received from Mr. Newman, and in those from Southport (examined 

 at the same time) the fibrous matter occurs only in very irregular and detached mass- 

 es, leaving considerable tracts of the rhizoma quite naked, and this fibrous matter ap- 

 pears to be different on different specimens ; but as an able and enthusiastic friend is 

 now engaged in the investigation of this portion of the subject, I shall briefly state 

 that my inference is that the supposed " cuticle of the rhizoma " is really a foreign 

 body. Thin transverse sections of the stem exhibit no trace whatever of a cortical lay- 

 er; except that the cellular tissue is surrounded by a single indurated stratum of 

 smaller cells of a brown colour, perfectly continuous with the rest of the cellular tis- 

 sue. No membranous cuticle could be detected, by scraping or otherwise, upon the 

 stem. On the rhizoma something like a cuticle was at times found in parts not coated 

 with fibrous matter ; but this, besides being immeasurably thinner, is diflferent in struc- 

 ture from the cuticle referred to in Mr. Newman's paper* (Phytol. 298), and can only 

 be detected by scraping the surface of the rhizoma. In some cases it seems to be quite 

 absent, and may therefore not belong to the plant. Mr. Newman's first and second 

 reasons do not appear to be well founded. Wherever the fibrous matter occurs I find 

 it matted together, and attached to the rhizoma in such a manner as to forbid the idea 

 of organic connexion ; and if there be any difference in the thickness of the ends of 

 each fibre, which is very doubtful, the position of the parts is at variance with Mr. 

 Newman's idea. The fibres indeedare often united together into fasciculi, presenting 

 an appearance very apt to mislead. After careful inspection of the colourless extremi- 

 ties of the " rhizoma," I retain the opinion expressed in my former remarks. In 

 opposition to the opinion that they are only growing extremities of the divisions of a 

 rhizoma, I would remark that I know of no instance where the growing j)arts of a rhi- 

 zoma have a downward or backward direction ; also that the supposed growing extre- 

 mities never develope themselves into scaly buds : — these are always laterally inserted, 

 and, if I mistake not, are at first immersed in the substance of the root, like the buds 

 in the tuber of a potato. On this point my former remarks require some correction. — 

 W. Wilson; Warrington, August 12, 1842. 



* Considerably more than ^^^j^ of an inch in thickness, and therefore easily seen when 

 a section of the rhizoma is under the microscope. 



