260 BOTANICAL GAZETTE [ocToser 
De Vries, H. Sur la fécondation hybride de l’endosperme. Rev. Gen. de 
Bot. 12 : 129-137. Igoo. 
NAWASCHIN, S. Ueber die Befruchtungsvorgange bei einigen Dicotyle- 
oneen. Ber. d. deutsch. bot. Gesell. 18: 224-230. 1900 
EXPLANATION OF PLATES XV AND XVI. 
Lomb 4 obj. and ocular 1, giving a magnification of 1260. The plates are 
reduced to one half the original size. A Bausch and Lomb jy obj. was used 
for studying minute details. | 
All the drawings are made with the aid of a camera lucida, Bauschand 
PLATE XV. Ertgeron Philadelphicus. 
Fic. 1. Embryo sac with fusing polar nuclei, ¢,; synergids, sy; &8§ 
nucleus, o. 
Fig. 2. Mature gti sac showing the long-beaked synergids, 5g €58) 
0, endosperm nucleus 
IG. 3. eee ction pollen tube, #7, with two intensely stained bodies, 
x; male cell fusing with the egg, a; second male cell fusing with the endo- 
sperm nucleus, &. 
IG. 4. First division of endosperm. 
Fig. 5. Later stage of endosperm division, showing cell plate and multi- : 
nucleate nuclei, : 
Sa ae ES icy EN, A acer ng gate SSS re 
Fig. 6. First division of fertilized egg. : 
PLATE XVI, Silphtum lacitntatum. 
Fic. 7. Fertilization ; pollen tube, AZ, passing into the sac; synergid, fe 
unknown bodies, x, male cell, sfx, lying against the nucleus of the egg 7 
male ra SP2, lying against the endosperm nucleus 
. Synergid, sy,; male cell, sf,, lying sense ‘pasoue 
this em cell was lost in sectioning); male cell, sf2, with large coll, 
against endosperm, ¢ a ; 
Fig. 9. Later pace of fertilization; pollen tube 7, synergid: | 
fusion of male cell with egg nucleus, a, fusion of male cell with endosper™ 
nucleus, 8, se 
FIG. 10. Second division of endosperm ; pollen tube, AZ, fertilized 6 
fo, dividing endosperm nuclei, e, ¢ 
o(a portion of - 
il, resting 
