OF ARTS AND SCIENCES. Ill 



VI. 



CONTRIBUTIONS FROM THE CRYPTOGAMIC LABORATORY OF 

 THE MUSEUM OF HARVARD UNIVERSITY. 



VII. — ON THE STRUCTURE OF THE FROND IN 

 CIIAMPIA PARVULA, Harv. 



By Robert Payne Bigelow. 



Presented June 10, 1887. 



There is a small group of the Floridece, consisting of the genera 

 Chylocladia, Lomentaria, and Champia, that is of particular interest 

 from the entirely anomalous condition of the frond. The frond is 

 hollow, is generally chambered, has thin walls, and contains peculiar 

 filaments running longitudinally close to the inner wall. Of this 

 group, Champia parvula and Lomentaria Bailey ana are abundant 

 along the New England coast south of Cape Cod. The former 

 species being the more convenient, was selected from a study 

 whieh I began in November last at the suggestion of my instructor 

 Dr. W. G. Fallow. 



In order to understand the points at issue, it is first necessary for 

 us to get a general idea of the structure of the plant that we are 

 studying. In general aspect the frond of Champia parvula is jointed, 

 cylindrical, and much branched ; forming a tuft four to six centimeters 

 high. The branches are given off at the joints, or constrictions ; 

 either singly, or else in pairs, or whorled (Plate, Fig. 1). If a portion 

 of the frond be cut open lengthwise and examined with a low power 

 of the microscope, it will be seen to be chambered, the barrel-shaped 

 chambers being separated by cellular diaphragms and becoming pro- 

 gressively smaller towards the apex (Figs. 1, 2). The diaphragms 

 are always at the joints or constrictions above referred to. 



A little more careful attention will reveal a number of straight 

 filaments (Fig. 2,/) running from the base of a branch to its tip, 

 where they converge. As far as my observations go, the number of 

 filaments in a branch may vary from eleven to fifteen. It will be 

 noticed that all the filaments in each chamber have projecting from 



