no 



slightly prolonged rachis, as seen in the accompanying 

 sketch, in which the leaf is shown detached and raised 



above the glumes, 

 leaves, I find, in the 

 minute 

 their 



On layin 





one of these 



open 



majority of cases, seated on a 



of the rachis, three stamens : 



prolongation 



immature green anthers lying side by side, and 

 being subtended by a membranous bract having a nar- 

 row, green, minutely mucronate keel. This bract occu- 

 pies the position of the superior palet ; but, unlike the 

 latter, it has a strongly pointed tip. In two instances, 

 I detected a still further change in this bract, which, 

 elevated yet higher within the investing sheath, had 

 assumed the form shown at b in the annexed fig- 

 ure. Here, the structure was intermediate between that 

 of a glume and that of the blade of a young leaf, the 

 bract being carinate, and strongly compressed ; having scarious mar- 

 gins, with about three veins on each side of the broad, dark green, 

 minutely mucronate keel ; and being tipped with a scabrous awn. 

 At the base was a rudimentary sheath, and in the axil of this were 

 seated the three stamens. The development of the sheath subsequent 

 to the formation of the lamina in these instances is in accordance 

 with observations already made by jVan Tieghem. In none of these 

 monstrous flowers is there the least trace of ovary or of the scales 

 which usually accompany it ; but in every case the stamens are pres- 



In the annexed figure, the metamorphosed flower 

 sented about double natural size : while the stamens {a) and the 



ent. 



IS repre- 



^JV-1JVV>«^ t,l.l_»'^»-ll, %JV_/L*WiS^ l-lllV L* i ttl ^KU-^ , ..i...l>^ t.i,^ .^»,w*.*-^..^ \"/ 



transformed superior palet (^) are shown magnified about four diam- 



eters. 



W 



96. Botanical News — The Color of Fhnvers.—kX a recent 

 meeting of the Vaudois Society of Natural Science, says La Nature, 

 Prof. Schnetzler read an interesting paper on the color of flowers. 

 Hitherto it has generally been supposed that the various colors ob- 

 served in plants were due to so many different matters — each color 

 being a different chemical combination without relation to the others. 

 No\v, however, Prof. Schnetzler shows by experiment that when the 

 color of a flower has been isolated by putting it in alcohol, one may, by 

 adding an acid or an alkali, obtain all the colors which plants exhibit. 

 Plants of paeony, for example, yield, when macerated in alcohol, a 

 violet-^red liquid. If some acid oxalate of potassa be added, the 

 liquid becomes pure red ; while soda changes it, according to the 

 proportion used, into violet, blue, or green. In the latter case, 

 the green liquid appears red by transmitted light, just 

 of chlorophyll does. The sepals of paeony, which are green, bor- 

 dered with red, become wholly red when placed in a solution of 

 acid oxalate vbinoxalate) of potassa. 

 may be obtained at will, may quite well be produced in the plant by 

 the same causes ; since, in all plants, there always exist acid or alka- 

 line matters. Further, it is stated that the transformation from green 

 into red, observed in the leaves of many plants in autumn, is due to 



XAnn. dts ScL Nat, Ser, 5, Tome XV., 1872, p. 236. 



as solution 



These changes of color, which 



