Transformation of ^'Eyilops into Wheat. 117 



which represent abortive awns. 2. In Triticum the spike is not 

 brittle, and is not detached when ripe ; the spikelets are con- 

 tracted at their base, which is not so broad as the rachis ; the 

 valves of the glumes are keeled, the nerves are few, and the awn 

 single. 



To this definition of the genera I will oppose the following 

 facts : j^gilops speltcpforjnis, that at least which M. Fabre ob- 

 tained after twelve years' cultivation, has a spike not brittle at 

 the base,^' and I am certain of this fact, as 1 shall explain further 

 on. The spikelets are not contracted inferiorly in Triticum 

 villosimi, P. Beauv., T. hordeaceum, Coss., and T. hicorne, Forsk., 

 and this base equals or exceeds the rachis in breadth. jEailops 

 triticoides and speltceformis have a keel upon the valves oi tiie 

 glume, less prominent than in Triticum, but occupying the 

 same position. Tiie nerves are numerous upon the glume ot 

 Triticum spelta, L. There exists only a single tootli represent- 

 ing the awn to the valves of the glume of ^Egilops speltoides, 

 Tausch. (which must not be confounded with ^gilops apelta- 

 formiSf Jordan) ; and except for this tooth the summit of these 

 valves is truncate and rounded at the sides. Triticum mono- 

 coccum, L,, has the same organs, terminated by two very strongly- 

 marked teeth, in which the nerves terminate, as is the case in 

 j.'Egilopi^ caudata, L., cylindrica, Flost., and ventricosa, Tausch. 

 Finally, the presence of a tooth representing a second awn is not 

 rare in Triticum spelta, L., and is also sometimes seen in Triti- 

 cum vulgai'e, Vill, durum, Desf., and arnyleum, Seringe. 



So that these distinctive characters have nothing precise about 

 them, and with regard to some species, it has been thought 

 necessary to transport them successively from the genus Tri- 

 ticum into the genus yEgilops, or vice versa, the generic question 

 not having been hitherto definitively settled in reference to these 

 species ; I may cite as examples Triticum hicorne, Forsk,, 

 jJigilops macrura and JEgilops loliacea, Jaub. and Spach, &c. 

 It is questionable, moreover, whether characters drawn from an 

 organ so unimportant as the glume of the Gramineae, which 

 represent simple bracts, are of a nature to form the sole basis ot 

 natural genera, Tlie fruits, on the contrary, which, since the 

 time of Tournefort, have been considered as furnishing generic 

 characters of high value, have been generally too much neglected 

 in the establishment of genera in this very natural family. Now 

 jTlgilops and Triticum have similar fruits, and these important 

 organs distinguish them very well from Agropyrum, Lolium, &c., 

 I will add, that the fact of hybridation between j^gilops and 

 Triticum goes to confirm the union of these two genera into one. 



* See M. Fabre's paper in the Journal of the Koyal Agricultural Society, 

 vol. XV. p. 175. 



