154 



MORPHOLOGY OF ANGIOSPERMS 



regarded the centrosome as a permanent organ performing an 

 important function in mitosis and in fertilization. Even the 

 " quadrille of the centers/' described by the zoologist Fol, was 

 identified by these observers. Centrosomes in the vascular 

 plants have been figured by many other prominent botanists, 

 including Humphrey, 16 Strasburger, 18 Campbell, 19 and Mot- 



D 



FIG. 70. Figures of centrosomes in vascular plants. A, Lilium Martagon, the reduction 

 division at germination of megaspore ; 12 chromosomes may be counted; x 600; 

 after GUIGNARD. IS B, Larix europaea, first division of pollen mother-cell ; x 600 ; 

 after STRASBURGER. 18 6 Y , Delphinium tricorne, first division of megaspore mother- 

 cell; "at upper pole are centrospheres " ; x 588; after MorriER. 21 /), Sagittaria 

 variabilis, first division of pollen mother-cell; x 640; after ScHAFFNER. 24 E, Lilium 

 candidum, reduction division at germination of megaspore ; after BERNARD.** F, 

 Psilotum triquetrum, first division of spore mother-cell; x 800; after HUMPHREY. 1 * 

 G, Equisetum telemateia, tetrad of four spores ; x 960 ; after CAMPBELL. 19 



tier 26 (Fig. 70). Most botanists, following Strasburger, have 

 publicly renounced any belief in the centrosome as an organ of 



