THE FLOWER DEFINED.— THE EMBRYO. 



LESSON II. 



THE FLOWER DEFINED— THE EMBETO. 



13. Flower defined. 14. Cryptogamia. 15. Parentage. 15 a. 

 Naked and covered spores. 16. Phanerogamia. 17. Naked and Cov- 

 ered Seeds. 18. Embryo-sac and Vesicle. 19. Male Flower. 20. 

 Parentage ; Fertilization ; Parthenogenesis. 



13. The Flower con- A ^,^^^^^s*^ " /^^^^"iA 

 sists of generative or- 

 gans and an Axis of 

 growth. It is the most 

 important part of the 

 plant. 



14. Cryptogamia. — _ 

 A. The female flower 'g°9°\'o:°/oy°op'o^?o 

 has several names, all ' .°'»'°6V».n"°o".S o"/ < 

 equivalent to the same 

 thing. The common 

 name in Seaweeds is 

 Oogonium, or Egg- 

 Seed (Gr. oon, egg, go- 

 nos, seed). In the Ferns 

 it is Archegonium, or 

 Chief Seed (Gr. arke, 

 chief). These oogonia 

 and archegonia are 

 often contained in a re- 

 ceptacle called sporan- yw. i.— a 



gium (plural sporan- ™ ing"^,'" "; oSgoniiim closed and ripenrng into an 



Oia), aSCUS, or pouch oospore; .antheridimn withered. X 3" d'am- D, 



'/ 1 ^ 1 .\ T oospore of (E'/o</o7ii»m ci7io/7(7n. E, zoospore of Yau- 



(plural aSCl), ana SeV- cheria after the withdrawal of the ciliae. r, zoospore 



eral Other names, to be »' «i<>go"'™ ^p-'-u-'s- xssodiam. 

 mentioned in their proper places. Each oogonium or arche- 

 gonium contains one or more spores ; each spore is the em- 

 bryo of the future plant (Fig. 1). This spore, even in the 

 highest cryptogam (plant of Cryptogamia), has no develop- 



1* 



Vuncherl i sessilis with oogonium and 

 B, oogonium open, Jintherozoids en- 



