CRYPTOGAMS 



337 



389. The antheridia. — Examine one of the male recep- 

 tacles on both surfaces and in vertical section. Notice the 

 tiny egg-shaped bodies sunk in little 

 cavities between the lobes just under 

 the upper epidermis (Fig. 478). These 

 are antheridia. When mature, they 

 rupture at the apex, and multitudes of 

 extremely small bodies, called anthero- 

 zoids, or spermatozoids, are discharged 

 from them, 



390. Archegonia. — Next examine one 

 of the female receptacles. Look on the 

 under surface, between the narrow divi- 

 sions of the receptacle, for radiating rows ^^^ 473 _ Longitudinal 



of flask-shaped bodies with their necks section of a male receptacle 



, , - in J J of marchantia polymorpha, 



turned downward, and all surrounded magnified: a, antheridia; 



by a toothed sheath or involucre (Fig. <-thaiius; ..ventral scales; 



•^ ^ r, rhizoids. 



479). These bodies are the archegonia, 

 or female organs, and correspond, loosely speaking, to the 

 ovaries of flowering plants. If the receptacle is a mature 

 one, the archegonia will be replaced 

 by the ripe spore cases (sporangia), 

 as at /, Fig. 479. 



Make enlarged drawings of the 

 upper surface of a male and a female 

 receptacle, and of a vertical section 

 of each, passing through an anther- 

 idium in the male, and an arche- 

 gonial row in the female receptacle. 

 Label the parts observed in each. 



391, Minute study of an arche- 

 gonium. — Place under the micro- 

 scope a very thin, longitudinal section 

 through a ray of a receptacle con- 

 taining a young archegonium, and observe that the latter 

 consists of a lower portion, the venter, v, Fig. 480, and an 



Fig. 479. — Under side of an 

 archegonial receptacle enlarged. 

 The archegonia are borne 

 among the hairs on the under 

 surface, which is presented to 

 view in the figure ; /, a spore 

 case. 



