OF THE UNITED STATES. 15 



more than two or three columns can find attachment, but generally the knots grow to 

 from half an inch to an inch and a half in diameter, before the gelatinous masses break 

 through the surface. The latter arise a short distance below the surface, and the outer 

 portion of the knot consisting of several layers of cork cells is raised in flattened papillae. 

 By the growth of the gelatinous masses the centre of each papilla is ruptured, and the 

 columns rise vertically. The margin of the raised papilla remains behind, as a sort of 

 collar around the base of each sporiferous mass. 



The shape of the fully developed knots is peculiar. In consequence of the fact that 

 the cells of the outer part of the knots multiply more rapidly than those near the base, the 

 knots become convex on the upper side and finally reniform, and are contracted beneath 

 and attached by a small base. It has generally been supposed that the knots are usually 

 outgrowths from the smaller branches, but such is not the case and, as far as I have been 

 able to ascertain, they originate in a leaf. When the knots have attained a considerable 

 size they appear to be terminal, because the branch above is pushed to one side. The 

 young knots begin to appear about the end of August, and often reach a considerable size 

 before winter. In the latitude of Cambridge, the gelatinous masses do not naturally 

 appear before May or, exceptionally perhaps, in April, but if knots are gathered in Febru- 

 ary or March and placed in a warm, moist place, they may be made to appear in from ten 

 days to a fortnight. The knots persist after the sporiferous masses have been quite washed 

 away, and from silvery-gray become brown and spongy, the surface being honeycombed, 

 the depressions being the spots from which the gelatinous masses have disappeared. In 

 by far the majority of cases, the knots gradually dry and drop off after having borne one 

 crop of spores. In rare instances, however, a new knot may grow from one side of the 

 old knot and bear a second crop of spores, but in this case the two portions remain 

 quite distinct, one part being old, shrivelled and weather-worn, and the new part succu- 

 lent, brownish-gray, and covered with sporiferous masses. By the nature of the knots 

 alone one can distinguish between this and the following species. The latter is perennial, 

 and between the sporiferous columns of one year one can easily see the scars of the last 

 year's masses. 



As far as concerns the gross appearance presented by G. macropus, the account given 

 by Schweinitz in the Syn. Fung. Am. Bor. is quite accurate. He states that the spe- 

 cies is rare in North Carolina, but common in Pennsylvania. He remarks also " capitulum 

 persistit per annum," from which one may infer that he recognized that the species was an 

 annual, a fact which succeeding writers have not sufficiently regarded. His description of 

 the cedar-apples themselves is so minute and accurate that there can be no doubt that 

 Schweinitz had either never seen the form described on a succeeding page as G. fuscum 

 var. glohosum, or at any rate clearly distinguished it from G. macropus. In the letter of 

 Wyman, published by Berkeley in the London Journal of Botany, Vol. iv, p. 316, an ac- 

 count is given of the germination of the spores and the distortions supposed to be produced 

 by G. macropus, but it is evident from the description that Wyman had confounded G. 

 macropus and G. clavipes. He says " I have made numerous searches for these parasites, 

 but have almost never detected them, except in the localities mentioned, viz. : the tufts 

 composed of acerose leaves and the " cedar apple." The tufts with acerose leaves are not 

 identical, as I believe, with the variety of form which occurs in the young shoots of the 



