22 



The wliole structure of Chondriis crlspus is A'eiy typical 

 for a water plant. No hard tissues and no special water 

 conducting cells are found. The plant as a whole is not 

 able to keep itself upright except when in the water. The 

 arrangement of the tissues is such that the plant is flexible, 

 but not very elastic. The shoot is bent to and fro by the 

 waves and the tides, but owing to the substance being very 

 tough the shoots are very rarely torn off the substratum. 

 Cltondrus crisjnis, is, in fact, very rarely found in the 

 entang-led masses of seaweed which are thrown on to the 

 beach after a gale. 



D. — The Reproductive Organs. 



The reproductive organs of Chondrus crispus are fairly 

 well known. 



Yegetative reproduction seems to play practically no 

 part in the life of marine plants. If it does occur in 

 isolated cases it certainly plays no important part in the 

 general biology either of the red algee in particular or the 

 sea in general. The power of reproduction is, in the case 

 of Chondrus crispus, confined to special cells or spores. 

 These may be produced asexually and sexually. In the 

 former case, they are called " tetraspores." In the latter 

 they are known as " carpospores," which are the ultimate 

 products of the fusion of the male nucleus of a " sperma- 

 tium " with the female nucleus of the "egg cell." This 

 fusion — or process of fertilisation — has never actually been 

 observed in our plant, but may safely be assumed 

 to occur. 



The nemathecia, the organs which produce the tetra- 

 spores, the antheridia giving rise to the spermatia and the 

 procarpia which harbour the egg cell, are never met with 

 on the same shoot. It is impossible to say from the 



