IIG 



A TEXT-BOOK OF BOTANY. 



\vc have also to note the character of the male gamete or sperm. 

 With the exception of the Cycads and Ginkgo, motile sperms are 





I"n.. -i. Development of garnet ophyte and embryo in one of the Coniferae. e, em- 

 hryo-sac (TIHV , a. art -henonium ; h, neck of archegonium; i, integument; p, pollen 



lube; n, nucellus; f, wing of seed; g. fibrovascular tissue; kz, canal cells of archegonium; 

 ka, beginning of embryo; k, nuclei; ws, tip of root; wh, root-cap; c, cotyledons; v. point of 

 growth of stem; s, stispensor. 



I, early stages of embryo-sac (e) ; II, young archegonium (a) after development of 

 neck cells (h), cell lumen (1); III, section of ovule with portion of attached seminiferous 

 ;cale (f) showing entrance of pollen tube; IV, embryo-sac with two developed archegonia; 

 Y. an h< ionium after fertilization, there being four nuclei at the lower part, only two of 

 which n; VI, further development of embryo; VII, VIII, IX, X, showing develop- 



ment !' lao'e tortuous suspensor. to which is attached the young embryo (ka) ; XI, XII, 

 mature embryo. After Strasburger. 



