Ill 



away from the conidiophore the stipe remains attached to the conidium, 

 and as it can always be seen readily when the conidium is in suitable posi- 

 tion, it serves as a ready means of recognizing the basal end of the conidium. 

 The stipe is equally obvious and distinguishable in H. Nos. 3, 4, 5, 13-16, 

 etc., though in H. No. 2 and certain other numbers the stipe is of somewhat 

 different type. While in very rare instances catenulation of conidia was 

 observed (Fig. 9, b] , this is apparently much less frequent than in the forms 



FIG. 9. H. No. 1: a, portion of a conidiophore bearing 

 conidia; b, catenulate conidia rarely occurring. 



described by Ravn. The apical end of the conidium is always obtuse, and is 

 marked by a pale spot that was mentioned by Ravn (91) as occurring in 

 H. teres, etc. Being of so distinctive a character, this end is always recog- 

 nizable when the conidium is in a suitable position. We have, then, reliable 

 means of identifying each end of the conidia: the basal stipe and the apical 

 spot (Fig. 10). The latter, though not characteristic of all Helmintho- 

 sporiums for example, H. Nos. 2, 29, and others lack it is characteristic 

 of H. Nos. 1, 3, 13-16, and others. 



The color of the conidia of H. No. 1 ranges from pale-straw to light 

 brown, and under some conditions shows a slight bluish-green tinge. While 

 H. Nos. 2 and 28 were distinctly and constantly different from H. No. 1 in 

 color, H. Nos. 1,3, 13-16, etc., were indistinguishable on a color basis. 



The conidial outer wall. This wall (the episporium of de Bary, 9), 

 which gives the color to the conidium, is extremely thin and very fragile 



