Miscellaneous. 135 



which perforate the latter. These tubes, which arc open at the 

 extreniitj', play the part of suckers, which pump in the fuvilla and 

 transmit it through the canals to the ovarj-. After fecundation, the 

 perforated pollen becomes dried up, whilst the stigma becomes folded 

 upon itself and withers. 



Consequently in the Gramineac two principal phenomena occur, 

 which are ■witnessed only in this family : — 



1. The elongation and expulsion of the filaments of the stamens. 



2. Fecundation by the perforation of the pollen. 

 These do not occur without reason. 



The seed, the result of fecundation, must occupy when perfectly 

 developed, the whole chamber formed by the union of the two 

 valves. Now the stamens occupy two-thirds of this space, and by 

 their volume they would obsti-uct the growth of the seed : they 

 must be expelled ; and hence the elongation of the filaments, and 

 the existence and the utility of the alimentary glands. 



As the fecundation is instantaneous, it is necessary that the fovilla 

 should instantaneousl}' penetrate to the ovar}^ throiigh the stigma, 

 the existence of which only lasts during the moment of fecundation ; 

 hence the structure of the stigma, and the phenomenon of the jjcr- 

 fo ration of the pollen. 



All the facts that I have just indicated may be verj- easily ob- 

 served in our cereals and the grasses of our meadows. To see the 

 details of the fecundation, it is only necessary to spKt the outer 

 valve longitudinally ; by separating the two parts of tliis valve, we 

 expose the organs of fecundation enclosed in the two curtains of the 

 inner valve, and the warmth of the breath or a ray of the sun is 

 sufficient to induce the phenomenon of fecundation. 



The natural hybridization of the Graminea? is impossible, from 

 the exact closure of the space or chamber containing the organs of 

 fecundation. — Comptcs Rendus, June 21, 1869, tome Ixviii. p. 1486. 



On a Trce-Frog in New Granada which secretes a Poison employed 

 by the Indians to poison their Arrotvs. By J. Escobar. 



This tree-frog appears to belong to the species called Phyllobaies 

 melanorhinus. It is known in the country by the names of liunilla 

 roja or roji^a. During life it is of a red tint shaded with Naples 

 yellow, and consequently rather yellowish red, like certain oranges, 

 the colour of which approaches that of the citron. The yellow pre- 

 dominates when the animal has been some time in alcohol. There 

 are two varieties — one in which the belly is black, and another in 

 which it is of the same colour as the upper parts. 



The poison is furnished by the dorsal region. It does not appear 

 to possess its properties completely unless it is collected at the moment 

 when the animal, still living, secretes it. To cause its secretion, 

 they introduce into the mouth of the frog a small wooden spatula, 

 and, taking great precautions in order not to produce injuries which 

 would cause death too rapidly, jiush it in so as to cause great suf- 

 fering, under the influence of which the whole upper surface of the 



