128 



hundred, it is probable that there is expended for the keeping of 

 living plants, a part of which die each year, nearly two million francs 

 per annum. Deduct what is proper to be charged to the amusement 

 of the public and the instruction of students, there still remains an 

 expenditure five times greater than that for Herbaria, and all for a 

 vastly inferior scientific result,* 



If governments could only agree to devote to the Horius siccus 

 a portion of the sura they apply to Botanical Gardens, a singular 

 impulse would be given to Botany. By promising, for instance, to 

 purchase collections of exstccatae from countries not yet explored, 

 they would advance the knowledge of all the plants of our epoch, in the 

 d6uble point of their nature and of their geographical distribution. ^ A 

 few thousand francs appropriated , to Herbaria, on the part of which 

 there might be an engagement to perform a certain amount of work 

 in the way of arrangement and of determination, would cause many 

 an existing collection to emerge from its present chaotic condition. 

 Anatomists, physiologists, horticulturists and directors of Botanic 

 Gardens could at least determine plants with certainty and without 

 too great trouble ; but, above all, authors of floras and of monographs 

 would be able to work with good materials, and would give us fewer 



of those deplorable descriptions that I have characterized as enig- 

 matical. 



loi. Double Flowers. — M, Heckel, in a note to the Academy 

 {Comptes Rendtis Oct. 4th, p. 581) attributes the formation of double 

 flowers, through petaloid developmentof the stamens, to long-continued 

 self-fertilization. His observations have been made on Convolvulics ar- 

 vensis,\j,; the flowers of which vary from deep rose-color, through white 

 with purplish markings, to immaculate white. He regards the last 

 named (pure white) as an example of the Darwinian idea that flowers 

 lose their color through close fertilization. The two white varieties ob- 

 served by M. Heckel were found to have a frequent tendency to be 

 affected with petalody of the stamens. Believing this to be due to the 

 same cause, close-fertilization, he undertook a series of experiments 

 on the plant, extending over a period of three years. The results 

 reached are in perfect accordance with the opinion that he had 

 formed, the third generation of the plants giving him an abundance 

 of double flowers. While M. Heckel's observations are important, 

 it cannot be that double flowers are wholly due to the causes he ad- 

 duces, since we have numerous examples of such among insect-fertil- 

 ized flowers, of which the rose furnishes a conspicuous example. 



*Tlie author elsewhere compares the value of plates, engravings, &c., with that 

 of dried specimens, and gives the following statistics of their relative cost : 



The number of botanical plates in existence exceeds 120,000, and they have 

 cost at least twenty-four million francs. This is the valuation of the stock deposit- 

 ed in libraries ! Have the results been commensurate with this vast expenditure ? 

 I will leave it to each one to answer this question according to his own ideas. But 

 as a term for the comparison, I will add, that a very rich Herbarium, of otie hun- 

 dred thousand species and one million specimens, does not represent more than 3 

 or 400.000 francs of successive expenditures. Seven or eight hundred Herbaria, 



equal in size to the best twenty in existence, would represent the same cost as the 

 plates. 



