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



adherent to the wall, are ordinarily to be found in the interior 

 of the pollen-tube, but now separate from one another. Some 

 have burst ; the solid bodies contained within them are diffused 

 in the cavity of the pollen-tube. Many of the still intact cells 

 are also frequently shrivelled up. Sometimes the pollen-tube 

 contains no cellular structures of any kind during the impreg- 

 nation ; but I never missed then the spindle-shaped and stick- 

 shaped bodies which were especially accumulated in the pouches 

 which penetrated into the corpuscula, being often joined in num- 

 bers ill to bundles. Pollen-tubes of this character could be more 

 readily dissected out free than those of the first kind, both in 

 Biotia and in Juniperus. Lastly, it happens that those large 

 cells are preserved, mostly the majority, in the pollen-tube, 

 during and after the impregnation ; but very much changed ; 

 flattened into a lenticular or meniscus form, firmly appressed to 

 the wall of the pollen-tube, sometimes at the side, sometimes at 

 the bottom. The central nucleus has now vanished ; in its place 

 are perceived in the cloudy (by transmitted light, yellowish) 

 contents of the cell, a definite number (8 — 16) of sharply cir- 

 cumscribed, circular, bright places (nuclei), between which run 

 delicate reticulated lines (the faces of contact of daughter-cells) 

 only to be detected with the best defining magnifiers. This is the 

 appearance in face ; in profile it is perceived that it is a simple 

 layer of prismatic cellules, into which the large cell has been 

 divided. In a single instance a fresh, freely swimming, globular, 

 large cell with a central nucleus was observed in the pollen-tube 

 of an ovule of Biotia orient alis, in two of the corpuscula of which 

 the pro-embryos had already made their appearance. In all 

 these cases those stick-shaped bodies were to be found, even 

 though sparingly, in the pollen-tubes, outside the large cells. 

 In pollen-tubes in this condition (which effect impregnation as 

 freely as the others) I never met with the protruded pouches 

 sent into the corpuscula. There is not the slightest difficulty 

 here in separating the pollen-tube, uninjured, from the albumen 

 and the fertilized corpuscula. 



The appearance of free globular cells in the widely expanded 

 end of the pollen -tube of Taxus baccata, formerly described and 

 figured by me*, is also in this plant followed by alterations of 

 these cells similar to those occurring in the Cupressinea. In 

 farther developed ovules, such cells appear firmly applied against 

 the wall of the pollen-tube, much flattened down, and divided 

 by walls standing crosswise and perpendicular to the mem- 

 brane of the pollen- tube. This condition of the said cells, the 

 size of which mostly exceeds that of the young pro-embryo, 



* Vergleichencle Unters. p. 132, t. 31. fig. 18. 



