SUSPECTED PARASITISM IN A MOSS. 211 



and in the older mosses no algae are found in contact with rhizoids. 

 But it is at the same time interesting to note that the rhizoidal system 

 is also very much reduced in extent by the death of the finer branches. 

 In these, there is a lot of food material found stored in the bigger 

 rhizoidal branches and most of the finer branches are shrivelled up 

 and non-functional. Here and there, a few algal masses are met with 

 on the plants at the axils of the leaves where some dirt has accumi- 

 lated and into those also rhizoids from the cortical cells of the stem 

 penetrate. But on the whole, in the older -plants the amount of 

 algae in their vicinity is very little when compared with the younger 

 plants. 



The absence of the algae in the later stages of the life of the moss 

 plant may be accounted for by the fact that the conditions near the 

 substratum are no longer favourable to the growth of algae. The 

 moss plants grow very close to each other and to nearly the height 

 of an inch, so that there is very little light available near the sub- 

 stratum. Higher up on the plants themselves the moisture conditions 

 are not favourable except in special situations. But where they 

 occur, rhizoids penetrate them. 



The above observations lead the author to believe that the com- 

 mon moss in Madras is parasitic on the blue green algae of the 

 substratum, when the moss plant is young and also in the protonema 

 stage. 



Explanation of Figures on page 209 



Pig. 1, Moss plant with algal masses attached to the rhizoids. 

 Pig. 2, Mass of protonema filamonts, some with and some 



without chloroplasts ; ends of filaments broken. One 



germinating gemma also shown. 

 Pig. 3. Rhizoidal branch encircling an algal colony. 

 Pig. 4, Rhizoidal branch with short cells encircling algal cells. 

 Pig. 5. Nostoc colony crushed showing main rhizoidal branches 



inside. 

 Fig. 6. Rhizoidal branches entering Nostoc colonies. 



