Dr. W. Hofmeister on the Fecundation of the Coniferse. 429 



XLII. — On the Fecundation of the Coniferae. 

 By Dr. W. Hofmeister*. 



Robert Brown's prophecy, that the Coniferse would furnish 

 the fittest material for the detection of the act of reproduction 

 in Phanerogamic plants, on account of the length of time occu- 

 pied in the development of their seeds, has not been fulfilled. 

 Long as the period is in the Coniferse, especially in the Firs, 

 between flowering and maturity, the development does not pro- 

 gress gradually, but in intermittent leaps ; in the most decisive 

 epochs it advances with great rapidity, and no external sign is 

 given of this. Difficulties are placed in the way of observation, 

 over and above those depending upon the structural conditions, 

 which explain sufficiently not only the difierences of opinion of 

 the many investigators who have busied themselves with this 

 question, but also the fact that a by no means inessential feature 

 of the process of development has hitherto escaped observation. 

 „j Schacht has lately published some remarks upon this sub- 

 jectf. The conclusions he draws from his latest observations, 

 which deviate from the account given by me three years ago, are 

 essentially as follows : — 



" Active filaments (spermatozoids) are not formed at any time 

 in the pollen-tube of the Coniferse I have examined. The act 

 of impregnation in the Coniferse is in no way comparable with 

 the formation of the germ of the higher Cryptogamia in the in- 

 terior of the 'germ-organ ' [Keim-organ ; this is the name applied 

 by Schacht to the archegonium] . 



. '^ No free cells originate in the corpuscula of the Coniferse. 

 What Hofmeister regarded as cells, are globular spaces filled 

 with clear fluid, bounded by a denser substance containing fine 

 granules; they are what are called pseudo-cells (vacuoles) not 

 uncommonly occurring elsewhere, and making their appearance 

 in the same way even in the pollen-tube of the Coniferse them- 

 selves * * *. From this it is clear that Hofmeister's view, that 

 a cell existing in the corpusculum is impregnated by the pollen- 

 tube, rests upon a misconception^ since no free cell exists in the 

 corpusculum before the entrance of the pollen-tube (p. 288). 



" When the pollen-tube has penetrated into the corpusculum 

 in the Scotch Fir {Pinus sylvestris) , it soon swells up slightly; it 

 displays itself as a small vesicle in the apex of the corpusculum. 

 By the formation of a horizontal septum a cell originates in this 

 vesicle ; this cell divides cross-ways into four daughter-cells. To 



* From the ' Flora,' Sept. 14th, 1854. Translated by Arthur Henfrev, 

 F.R.S. &c. 



t Beitrage zur Anatomie und Physiologie der Gewachse, Berlin, 1854, 

 pp. 287 and 324. 



