50 



BOTANY. 



They usually grow attached to rocks, shells, wood, or other 

 plants, such as the kelps and even the larger red seaweeds. 

 They are most abundant in the warmer seas, but still a con- 

 siderable number may be found in all parts of the ocean, even 

 extending into the Arctic regions. 



FIG. 29. A, a red seaweed (Callithamnion) , of the natural size. B, a piece of 

 the same, x 50. t, tetraspores. C i-v, successive stages in the development 

 of the tetraspores, x 150. D i, n, young procarps. tr. trichogyne. in, 

 young; iv, ripe spore fruit, i, in, x 150. iv, x 50. E, an antheridium, 

 x 150. F, spore fruit of Polysiphonia. The spores are here surrounded by 

 a case, x 50. 



The methods of reproduction may be best illustrated by a 

 specific example, and preferably one of the simpler ones, as 

 these are most readily studied microscopically. 



The form here illustrated (Callithamnion) grows attached to 

 wharves, etc., below low-water mark, and is extremely delicate, 

 collapsing completely when removed from the water. The 

 color is a bright rosy red, and with its graceful form and ex- 

 treme delicacy it makes one of the most beautiful of the group. 



