262 PROCEEDINGS OF THE AMERICAN ACADEMY. 



necessity for the rapid growth of the peridium to cover it. Inter- 

 stitial cells are present, and do not show anything unusual. The 

 usual double nuclei were easily demonstrated in all the various parts 

 of the iecidium. 



This iecidium proved more favorable than some to demonstrate the 

 connection of the basidia with the fertile hyphte. In one fortunate 

 macerated preparation a somewhat tortuous hyplia was seen, from 

 which branches arose that terminated directly in the basidia (Fig. 11). 

 The character of the leaf was not favorable for the study of the 

 younger stages, as the compacted condition of the tissue and the 

 presence of much chlorophyll obscured the young primordia. Never- 

 theless, several interesting stages were seen that are worthy of note 

 since they help to substantiate the observations made on the other 

 secidia. In Figure 10 a section of a young a^cidium is shown where 

 the fertile hypha has pushed its way into the already fully developed 

 pseudo-parenchyma. From the fertile hypha, in which many nuclei 

 could be made out, there have arisen the first buds from which event- 

 ually the basidia and spores will be formed. Unfortunately this 

 otherwise excellent section was marred by the fact that the hypha 

 was cut off only a short distance below the placp where it had begun 

 to bud out. Its connection with the hypha below, as indicafed by the 

 dotted lines, was only inferred by the similarity of their contents and 

 general appearance. At this early stage no septa could be seen that 

 cut off the buds from the parent hypha. Other stages of a similar 

 sort, some younger and others older, were found, but none showed as 

 clearly as the one just described. A very much younger condition, 

 where the fertile hypha is but a simple thread with a rounded end 

 and rich in granular contents, was perhaps the earliest condition 

 observed. In some of the larger aecidia, which however never ap- 

 proached the size often attained by the occidium on Peltandra, ther 

 were apparently more than one point of origin for the basidia. 



-^ciDiuM ON Anemone. 



This form, which is ^cidium punctatum Pers., is in many respects 

 unfavorable for examination, but, as it was apparent that it presented 

 some variation from the type already described, some work was under- 

 taken on it. The gecidia do not occur in clusters, as in some other 

 cases, but are more or less scattered over the under side of the leaf; 

 but they have a certain advantage over other fecidia in that the 

 spermogonia being so very superficial there is never any danger of 

 confusing the young stages of these two organs. 



