i9"] BARRETT— BLASTOCLADI A 365 



mature 



Thaxter 



mature 



smooth, and an inner 



pitted. He did not study a section of the wall, hence was not able 

 to determine the structure definitely. They possess several large 

 oil globules, are oval to pyriform, and vary in form almost as much 

 as the zoosporangia. 







In B. ramosa the resting sporangia, or spores, are "bluntly 

 rounded, gradually narrower toward a truncate base, and about 

 30X11 /*." In this species the resting spores are less variable in 

 form than those of B. Pringsheimii, but vary somewhat in size. 

 The walls are very little thicker than those of the sporangia. 

 Resting spores of neither species were seen to discharge zoospores 

 or to germinate. 



The resting sporangia of B. strangulata, for such they are, as will 

 be shown later, are very constant in form and vary only slightly in 

 size. They are ovate in form, with the narrower basal end truncate 

 (%• x 5)- As previously noted, they occur at almost any age of the 

 plant, depending on the conditions of growth, and remain attached 

 at maturity. They have their origin, in general, in the same 

 manner as the zoosporangia, and in the younger stages cannot be 

 distinguished from them. The wall begins to thicken early, and 

 this, together with the absence of papillae, indicates that resting 



ingr When thev are mature 



three 



middle, thick, perforated, and orange colored. The peculi 



mi 



mature resting sporangia. The pores are conical in 



with 



The greatest diameter is 



view 



0.8 \l and the least 0.3/*. Fig. 16 sh 

 fig- 17 is a diagrammatic representation of a cross-section, showing 

 the pores and the inner and outer walls. The pores are more or 

 less regularly arranged in rows, as seen in fig. 15. 



mature 



m 



bodies of a similar nature. In describing these bodies for B. 

 Pringsheimii, Petersen (4) says: "Peculiar pointed or rounded 



