154 B0TAN7, 



ids they attach themselves to the trichogyne, as shown in 

 Pig. 77. The result of this contact of the antherozoids with 

 the trichogyne is the fertilization of the carpogone, which 

 immediately enlarges and at the same time undergoes 

 division into many cells, which grow into short, crowded 

 branches, hearing a spore at the end of each [D and JS, Fig. 

 77). This growth, which includes the spores and the short 

 branches which bear them, and which resulted from the 

 fertilization of the carpogone, is the spore-fruit {sporocarp) 

 of these plants. In the genus under consideration the 

 spore-fruit is a comparatively simple growth, as compared 

 with the degree of complexity it reaches in some other 

 orders of this class. 



319. In some other cases (Lejolisia, etc.), the carpogone, 

 before fertilization, consists of several cells {A, b, Fig. 77). 

 Upon fertilization taking place, the outer cells of the carpo- 

 gone divide, and develop into articulated branches which 

 lie side by side and form a more or less spherical envelope, 

 the so-called " pericarp." In the mean time the central cell 

 of the carpogone produces outgrowths or short branches 

 which eventually bear spores, occupying the cavity of the 

 pericarp {A, s, Fig. 77). The spore-fruit here consists 

 of a fertile part which bears spores, and a sterile part 

 which serves as a protection or covering. In technical 

 works the spore-fruit is called a " cystocarp." 



Practical Studies. — There are many orders of the Red Seaweeds, 

 but it is unnecessary to notice them here particularly. About one 

 hundred species occur along the New England coast, and the number 

 is greatly increased as we pass to the southward. 



It is diflScult for the student to study the plants of this class away 

 from the seashore, and as a rule it is perhaps as well for the beginner 

 to content himself with only a general examination of such specimens 

 as may be accessible. 



Specimens for the study of the structure should be preserved in 



