Chap. 1. SECKETION OP NECTAR. 41 



with their much stronger ones, could penetrate with ease 

 the soft inner membrane of the nectaries of the above- 

 named Orchids. Dr. H. Miiller is also convinced* that 

 insects puncture the thickened bases of the standard 

 petals of the Laburnum,t and perhaps tha petals of 

 some other flowers, so as to obtain the inclu'lod fluid. 



The various kinds of bees which I saw vi'jiting the 

 flowers of Orchis morio remained for some time with 

 their proboscides inserted into the dry nefftiries, and 

 I distinctly sav this organ in constant moAcment. I 

 observed the same fact with Empis in the case of 0. 

 maculata ; and on afterwards opening several of the 

 nectaries, I occasionally detected minute brown specks, 

 due as I believe to the punctures made some time 

 before by these flies. Dr. H. Miiller, who has often 

 watched bees at work on several species of Otchis, the 

 nectaries of which do not contain any free net star, fully 

 accepts my view.| On the other hand, Delpino still 

 maintains that Sprengel is right, and that insects are 

 continually deceived by the presence of a nectary, 

 though this contains no nectar. § His belief is founded 

 chiefly on a statement by Sprengel that insects soon 

 find out that it is of no use to visit the nectaries of 

 these orchids, as shown by their fertilising only the 



* ' Die Befruchtung,' &c. p. 235. tinct case, namely, tlie presence 

 t Treviranus confirms (' Bot. of nectar in several monocotyle- 

 Zeltung,' 1863, p. 10) a statement donous plants (as described by 

 made by Salisbury, tliat when the Ad. Brongniart in ' Bull. Soc. Bot. 

 filaments in the flowers of another de Prance,' tom. 1. 1854, p. 75) 

 leguminous plant, Edwardsia, fall between the two walls (^feuillets) 

 off, or when they are cautiously which form the divisions of the 

 separated, a large quantity of ovarium. But the nectar in this 

 sweet fluid flows from the points case is conducted to the outside 

 of separation ; and as beforehaud by a channel ; and the secreting 

 there was no trace of any such surface is homologically an ex- 

 fluid, it must have been contained, terior surface, 

 fts Treviranus remarks, within the % 'Die Befruchtung,' &c. p. 8-1-. 

 cellular tissue. I mny add an ap- § ' Ult. Osservazioni sulJa Di- 

 parently similar, but really dis- cogamia,' 1875, p. 121. 



