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■easterly banks of the little-frequented driveway, where the automobile is hap- 

 pily excluded, and here the snow and ice of winter prevail longer than for many 

 a mile around. 



In the upper portion of the Wissahickon Valley began my more intensive 

 study of the mosses. It is true: hair cap, funaria, sphagna, and other undif- 

 ferentiated species just mentally grouped as "moss," had long been familiar 

 objects, but a certain early winter's day marked a line of departure in botanical 

 pursuits, filled with determination to intimately know the bryophytes of the 

 Philadelphia neighborhood. 



It was a cold gray afternoon with a feeling of snow in the air. The leaves 

 of deciduous trees had fallen, to cover the earth with a russet mantle. A car- 

 dinal flashed red among the bare oaks and birches and the abundant hemlock 

 displayed a sombre green. Green, too, were the Christmas ferns and green 

 were many of our friends, the mosses. 



The banks were evidently clothed with a number of species of which two 

 predominated. These mosses were found to be Dicranella heteromalla and 

 Catharinea angustata. The former in ample clumps with soft, slender, green 

 leaves appearing as if brushed to one side, was frequently fertile. The glossy 

 brown sporophytes were conspicuous, the capsules in general still holding their 

 lids, although a few, of duller brown, already showed the bright red teeth of 

 the dicranaceous peristome, so attractive under the hand-lens. What objects 

 of never-failing interest in their fine adaptations for spore dissemination are 

 these peristomes of the mosses! Unforgetable moments of delight may be spent 

 in contemplating under low powers of the compound microscope their delicate 

 colors and markings and infinite variety. Ceratodon, Bartramia, Funaria, 

 Mnium — common genera readily collected by the amateur — all possess peri- 

 stomes of rare beauty with which every student of the mosses should be familiar. 



The other first acquaintance of that wintry day, Catharinea angustata, was 

 perhaps even more common than the Dicranella. The plants with curled leaves, 

 •olive green to brownish red in color, appeared along the banks on every hand 

 through the valley of the Wissahickon and, when present, the sporophytes of 

 deep claret red stood in thick companies retaining their long-pointed opercula, 

 which are not lost until early spring. Here is another peristome to examine. 

 In dry weather a disk called the epiphragm is borne aloft by the thick teeth and 

 from beneath it the spores are sifted out. There is a tantalizing impulse to 

 pass one's hand over the mature capsules, when clouds of spores arise, resem- 

 bling the fumes of nitrous oxide gas which escape from nitric acid wherein 

 copper is dissolving. The larger Catharinea undulata was also seen, but only 

 later was it clearly differentiated from its more common brother. 



Dicranella and Catharinea, then, were my first real acquaintances among 

 the mosses and, toward dusk, when I returned home, that day of long ago, amid 

 the swirling snowflakes at last released from the dun sky, I brought with me 

 specimens of these and memories to be treasured throughout ensuing years of 

 moss collecting and microscopic study. 



