Intelligence and Miscellaneous Articles, 293 



the good fortune to meet with Mr. Brown, during his journey through 

 Germany (in 1833), will remember that he carried with him impreg- 

 nated ovaria in spirits, and with his accustomed kindness showed the 

 entrance of the pollen tubes into the ovulum to every one who took 

 any interest in the subject. Notwithstanding this, Corda, a few- 

 lines lower down, affects an unpardonable ignorance of this fact, in 

 order to arrogate to himself a discovery which Amici (already in 

 1830) and Mr. Brown had made long before him Inconsist- 

 encies are also evident in the figures. Fig. 14j for instance ; the 

 embryonal sac is termed nucula, (should be nucleus,^ and the pollen 

 tubes enter it in order to produce, by their emissions, heaven knows 

 what kind of an imaginary figure. Fig. 22: here the embryonal sac 

 is even called embryo (E), and the pollen tubes run around it. But 

 it would be an herculean task to follow, step by step, this memoir. 

 It will here suffice to observe that, with the exception of a few points 

 of minor importance, everything almost surpasses the limits of pos- 

 sible error, and does not in the least represent nature. I refer every 

 one, who has even but little practice in such examinations, to na- 

 ture herself, as the observations are not of the most difficult kind." 



ON THE DEVELOPMENT OF AN ELECTRIC CURRENT ACCOM- 

 PANYING THE CONTRACTION OF THE MUSCULAR FIBRE. BY 

 DR. J. L. PREVOST. 



About fourteen years ago we published, together with M. Dumas, 

 a memoir on the muscular fibre, in which we determined that the 

 contraction of the muscles was owing to the sinuous flection of the 

 fibres ; we attributed the flection to the attraction of the nervous 

 reticula, which placed at short distances from one another and per- 

 pendicularly to the direction of the muscular fibres, approached each 

 other when an electric current, emanating from the cerebro-spinal 

 system, passed through them. Our observations having been made 

 with a microscope inferior in goodness to those constructed by 

 Amici, the true (Hsposition of the motive apparatus escaped us, and 

 our assertion was considered an ingenious hypothesis deficient in 

 the investigations requisite for its confirmation. Last summer I 

 again resumed this subject with better means, and the following is 

 one of the results which I obtained. If we observe the muscles of 

 a frog with a magnifying power of four hundred, we perceive that 

 they are composed of small cylinders, the diameter of which varies 

 from five to twenty hundredths of a millimetre : these cylinders are 

 connected with each pther by the cellular tissue, through which pass 

 from one cylinder to the other the nerves and vessels. 



The fibres arranged thus parallel to one another, fix themselves, 

 without separating, either to the tendons or to the aponeuroses 

 which correspond to their extremities, the latter becoming round 

 and disposing themselves in a small cavity placed on the tendon to 

 receive them. 



ITie muscular cylinders, which we shall call fibres, are themselves 

 composed of fibrillac, the diameter of which amounts to about ^tt 



