Sckrader: observations on alaria nana. 159 



The stipe is rather dark in color, especially in older plants. 

 Its general shape is terete, but the upper or rachis portion, 

 upon which the gonidiophylls are borne, becomes somewhat 

 elliptical in shape as it reaches the lamina, where it becomes 

 the midrib. The surface of the stipe is smooth ; it is tough, 

 and does not branch although it gives rise to the gonidiophylls 

 in the area just below the lamina. 



The lamina is lighter in color than the stipe. It is rather 

 thin and elastic, and varies in maximum width from about one 

 eighth to one sixth of its length. A thick midrib runs through 

 the center, and the lamina proper may be considered as simply 

 a flattened expansion of the midrib. In perfect specimens the 

 lamina tapers somewhat at the tip, but owing to the action of 

 the surf, the lamina is usually torn considerably at its upper end, 

 sometimes only the midrib remaining to show the former length. 



The gonidiophylls are proliferations of the stipe, situated just 

 below the base of the lamina. When they first appear they 

 look like little, conical, smooth outgrowths, on the side of the 

 stipe. As they elongate, they flatten out. They vary con- 

 siderably in number, according to the size and age of the plant 

 on which they are borne, and from thirty to forty or more in 

 mature specimens is nothing unusual. The oldest gonidiophylls 

 are found nearest the base of the cluster, the youngest nearest 

 the lamina. They have no midrib, nor any similar structure, 

 but their base is somewhat thickened and narrowed into a short 

 stalk, which does not differ in structure from the rest of the 

 gonidiophyll except that it is sterile. The color is almost as 

 dark as that of the stipe. Patches of sori, consisting of gonid- 

 angia and paraphyses are found on both sides, except in the 

 case of the very young gonidiophylls. 



Anatomy. 



The anatomical study was based upon slides, made from both 

 young and old material. Most of the material was killed in 

 formalin solution four per cent, and before being used was 

 washed for twenty-four hours in running water, dehydrated and 

 embedded in paraffin by the usual methods. Most of the sec- 

 tions were stained on the slide, and mounted in Canada balsam, 

 but in some cases it was found that heating the sections in order 

 to fasten them to the slide distorted them. In such cases the 

 sections were dissolved out in xylol, gradually brought into 



