Developmoit of SporOgenoiis Tissue 261 



these stalks to the petiole ranged from the base of the petiole to the 

 base of the blade of the leaf. Observations made on trees in the state 

 park at Spencer, Indiana, and on street trees in Crawfordsville and 

 Ladoga, Indiana, revealed the same conditions. Neither the age nor the 

 vigor of the tree seemed to make any difference in the relative number 

 or kind of stipules produced. 



When one sees a leaf M?ith stipules like those in figures 1 and 2, 

 there seems to be nothing unusual; but on observing one with stipules 

 like those in figures 3, 5 and 11 where one sees apparently the normal 

 stipule plus something else, there is a question. Are these structures 

 a part of the so called "normal stipule", or are they structures originat- 

 ing in the axils of the stipules? Some leaves would seem to indicate 

 that they were simply enlargements of the normal stipule (fig. 12). 

 But other leaves show the slender stalks of the unusual stipules coming 

 from the axils of the normal stipules. Even when these stalks come 

 apparently from different places on the petiole, they can usually be 

 traced by a ridge on the petiole back to the axil of the normal stipule 

 (figs. 10 and 11). Sometimes three of these stipules may be found on 

 one leaf (fig. 14), or one may fork as is shown in figures 10 and 13. 

 Or, this stipule may be sessile at the base of the leaf blade, appear- 

 ing at first glance as a lobe of the leaf (fig. 9). The blade of the 

 stipule may be very simple and entire as is seen in figure 4, A ; or 

 it may be aecidulated and variously lobed as is shown in figure 6. The 

 lobes of the stipule are frequently similar to those of the leaf blade. 



By late summer, a few of these stipules had fallen, leaving only 

 a slight scar. As far as the writer could ascertain, only a very few 

 of these unusual stipules might be classified as "early deciduous". A 

 great many of the leaves examined late in the autumn still retained 

 their stipules. There seemed to be no tendency, except in a few instances 

 for the stipules to be shed before the leaves fell. 



In conclusion it might be said that all the trees examined had at 

 least a few leaves with unusual stipules, but some trees showed a 

 much larger proportion of stipulate leaves than others. Whether or 

 not there is something inherent in the tree that causes it to produce 

 these unusual stipules is not known. Observations of certain trees of 

 opposite tendencies made from year to year, and seedlings from these 

 trees might in a measure help to solve the problem. But before a 

 definite conclusion can be formulated, it seems necessary to study a 

 large number of trees of different localities, and also to study the origin 

 of these unusual stipules morphologically. 



DEVELOPMENT OF SPOROGENOUS TISSUE IN THE 



FOOT OF THE SPOROPHYTE OF PORELLA 



NAVICULARIS. 



Flora Anderson, Indiana University. 



From fresh material of Porelln navicularis sent from Corvallis, 

 Oregon, in the fall of 1920, quite a number of young sporophytes were 



