ERRATA, ALTERATIONS AND ADDITIONS. 



VOL. XXII. 



pp. 134, 135. Put the expressions marked (8),(9),(B).(C), each=0. 



VOL. XXIV. 



'dv. 



p. 44, lines 18 and 19. Forc=r^dv,c'=r'^dvhc.,readc- 



dt 



r'^dv 

 c'=—jT-, he. p. 300, lines 3, 4, 5. For the first member of the 



sentence beginning, 'A quantity, &c.' read, The increments of two 

 quantities whose rates of increase are different in kind, let those in- 

 crements be ever so small, cannot be compared together. 



In binding, place Dr Hare's plates, as follows: evolution of silicon, now facing 

 p. 253, to face p. 248; that on the evolution of boron, which is the second as they 

 now stand, must face p. 250 ; that on the valve cock, the third as they now stand, to 

 face p. 251. Page 237, line 2 from the top, dele and. 



VOL. XXV. 



Page 73, April 20, for Cynoglossum, read Onosmodium hispidum; May 2, dele 

 all under this head and substitute Argemone mexicana, var. albiflora, b. b. P. 75 

 fig. 5, after Argemone georgiana, instead of the present paragraph, read— Petals 

 from 7 to 9, white ; capsules semi-valvular, 5 to 6 valved. I have seen this plant 

 only in gardens. The genus Argemone is described by Nuttall and Elliott as hav- 

 ing six petals, which is true in those specimens of A. mexicana which I have ex- 

 amined, and which is either native or naturalized in the streets of Newborn. It 

 therefore becomes a question, whether the additional petals, observed in the white 

 flowered Argemone, are the effect ot cultivation, developing, entirely or partially, 

 another whorl of petals. If this hypothesis be assumed, I do not know that this 

 plant will be found to be more than a variety of Argemone mexicana. 



To the article " New localities of plants," p. 77, add the following. 



Tripsacum dactyloides, and T. monostachyon. 



On Neuse River, near Newbern, and on Cape Fear River, near Wilmington. 

 These grasses, under the nameof "Gama grass," have lately acquired, in the 

 South, considerable celebi ity, and are beginning to be cultivated as a provender for 

 horses and other cattle. Their product is said to be very great. 



Elliott's description of T. dactyloides is defective and erroneous. It is as follows : 

 "Spikes numerous, (3-4,) aggregate," — and in the extended description, "Flowers 

 in terminal spikes; spikes three to four, (when four, brachiately opposite .') bearing 

 flowers on one (the interior) side. Fertile florets two to four, at the base of the 

 spike," &c. 



This description might be given more correctly thus: "Flowers in terminal 

 spikes ; central spikes (those of the stem) aggregate, two to four ; bearing flowers 

 sometimes alternately on two sides, sometimes on one (the exterior) side. Fertile 

 florets two to eight, at the base of the spike, &c. ; spikes of the branches (terminal) 

 solitary, somewhat cylindrical." (Precisely similar to those of T. monostachyon.) 



This last circumstance, which has not been noticed by botanical writers, tends to 

 confirm the suspicion, entertained by Pursh. that these are one species, varied only 

 by accidental circumstances. Should this opinion be ultimately established, and the 

 abolition of both specific names become necessary, I would suggest as the substitute 

 Tripsacum heterostaehyon, in allusion to the diversity of its spikes. 



