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STATE BOARD OF AGRICULTURE 



velope, with flagella running down to the centrally stained portion and pro- 

 jecting from each end of this destained envelope. Individuals of this type 

 may be abnost spherical and occur in pairs in the same cell. (4) Very small, 

 elongated jflagellates, less than 0.5 micron in diameter and sunilar to type 1. 

 These are common in sieve and parenchjana cells and probably represent very 

 young forms of type 1. (5) Deeph' stained oval bodies with degenerate 

 flagella and occasional remnants of an outer envelope. These may be 

 encysted forms. (6) Small, elongated, non-flagellate bodies which occur in 

 great numbers in the degenerate chloroplasts of the sub-epidermal cells of 



Fig. 2. Longitudinal section through the phloem of b^an plant affected with mosaic, showmg flagel- 

 lated organisms lyiag in the g eve tubjj and siev-ri pirenrhyma calls. X 650. 



A. Body of the flagellates. 



B. Flagellum. 



diseased stems and petioles. They may entirely fill the cell lumen by their 

 escape from the chloroplasts or remain imprisoned within them (Fig. 7). 

 These organisms are very variable in size but are much smaller than the 

 flagellate forms. Since a detailed study will have to bs made of all thsse 

 types before they can be assigned a place in the life history of this organism 

 they are given only brief mention here, and will be described fully in a future 

 publication. Such diversity of form indicates the probability of extreme 



