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and the White Clover, the Rust stages so abundant as to de- 

 stroy it is estimated, 50 per cent, of the second or "rowen" crop. 

 During 1890 it was far less abundant. Although in the autumn 

 it was plentiful, it did not injure the clover to a great extent. 



In the scientific discussion of the parasite, which follows, we 

 will consider, first the Vegetative characters, then the Reproduc- 

 tive organs, following with a description of our experiments. 



Fig. 2 — Transection of a Clover leaflet, showing the roundish leaf -cells, a group 

 of vascular cells in the middle, belonging to the mid-vein, and the epider- 

 mis, raised and broken in places by the pressure of the Rust spores. The 

 Rust spores {II stage), in sori or masses, are globose, granular and mostly 

 attached to the mycelium, which cau be seen ramifying between the leaf-cells. 



THE MYCELIUM. 



This is the vegetative portion living and growing inside the 

 living clover leaves and stems, and which gives rise to the three 

 spore forms described below. It has the same general characters 

 in each, and consists of slender, colorless, much-branched threads 

 (Fig. 2) which are more or less tortuous. These filaments, known 

 as hyphae, obtain nourishment from the cells of the leaf of the 

 host plant among which they ramify, but which they apparently 

 never enter. 



Repeated sections of the petioles of affected leaves were made 

 but no traces of mycelium could be found in them. This seems 

 to show that the mycelium is limited in extent and does not de- 



