234 PROCEEDINGS OF THE ACADEMY OF 



lutesccns.) They are suborbicular in outline, lobed and rooting underneath, 

 as in the true terrestrial species. They also have rudimentary scales at the 

 apices of the lobes underneath. These fronds become immersed by the au- 

 tumn rains, and during the winter the apices of the lobes thicken and expand 

 greatly. These apices being destitute of rootlets and extremely buoyant, 

 gradually assume a vertical position in the bottom of the pool, and at length 

 (in the spring) become detached and rise to the surface of the water, (where 

 they float in a horizontal position,) often carrying with them portious of the 

 effete base of the frond. In the meantime the scales develop into long purple 

 fringes. Thesefioating apices alone constitute the L. natans of Linnseus and authors : 

 (vide Aust. Hep. Exsic. N. 144, A. ; also Lindbg. Monogr., p. 115, t. 31 and 32 ; 

 etc.) They fruit copiously in the vicinity of Albany, N. Y., in the months of 

 May and June (Prof. C. H. Peck). Sometimes the autumn fronds do not 

 become immersed, in this case they remain whole ; again the fertile fronds 

 are often left upon the mud by the dessication of the pool in summer ; in this 

 case they are plainly continuous from the apex: (vide Hep. Exsic. N. 145; 

 also Herb. Tayl. [in part), under the name of '■'■ Riccia velutina. — N. Amer. Drum- 

 mond." 



Riccia lutescens, Schweinitz. 



A single frond only of this species was found by me iu Sept. 1858, at Closter, 

 N. J. This frond contained a single sporangium I which is about as in R. 

 crjistallina. The spores are also as in that species. During the past eight years 

 I have not only watched this plant in all the stages of its growth, from the 

 time of its first appearance in the month of June, until its final disappear- 

 ance in winter, but have collected many specimens of it in the mature state. 

 I have also received numerous specimens of it from many localities, from 

 New England to Canada and Missouri ; but not a single one of these speci- 

 mens shows any trace either of fruit or other kind of reproductive organ 

 whatever ! and it is still a mystery how the plant reproduces itself. The 

 young plants make their appearance in great profusion, in the bottoms of 

 exsiccated ditches, &c., in the beginning of summer. These rapidly develop 

 into the sterile plant, which has been most accurately described and figured 

 by Mr SuUivant : {Mem. Amer. Acad. Arts cj- Sci. (Boston) 4, p. 176, t. 4.) No 

 rootlets are produced underneath the frond above the middle ; and asthe ditches 

 become filled with water late in autumn, the fragile laciniae break asunder 

 near the middle, in consequence of the extreme buoyancy of their apices. The 

 detached pieces (or apices) rise to the surface of the water, where they re- 

 main suspended in an oblique position (the extreme apex only reaching 

 the surface), until they become frozen up in the ice. Upon the ice disap- 

 pearing in the spring, no trace of any portion of the plant is to be found 1 



The following reports were read, and referred to the Publication 

 Committee : 



REPORT OF THE CURATORS. 



In presenting the annual report, the Curators embrace the opportunity of 

 congratulating the Academy on the near prospect of procuring a new and 

 suitable building to accommodate its now crowded and ever increasing col- 

 lections, both of the museum and library. A plan of the building prepared 

 by Mr. Windrum, the architect, at the suggestion of and in conjunction with 

 a committee of the trustees of the building fund, has been approved by the 

 latter. It is proposed to commence with the foundation of the building, the 

 coming spring, on the fine property obtained by the contributors of the 

 building fund, on the southwest corner of 19th and Race streets, and oppo- 

 site the beautiful Logan Square. The style of the building is college gothic, 



[Dec. 



