OF ARTS AND SCIENCES. 61 



order. The carpospores of Ohoreocolax Polysiphonice, it will be re- 

 membered, were found to be borne singly all over the inner surface 

 of the cavity, on cells or filaments projecting into its cavity. This 

 fundamental difference in structure certainly makes it impossible to 

 consider C. Polyslphonice one of the Gelidiaceae. The condition of 

 the cystocarp approaches far more nearly that found in the Chajtangi- 

 acese than in any other order. I examined cvstocarpic specimens of 

 Chcetangium ornaticm, in order to compare them with those of Clio- 

 ViOcolax Polysiphonice. Although the cystocarp of Chaetangium is 

 somewhat more complicated than that of Choreocolax, there is a great 

 resemblance between the two. The spores are borne in Chjetungium 

 on filaments projecting into the cavity of the cystocarp, much in the 

 same way as was observed in Choreocolax Polysiphonice. The fila- 

 ments in Chaetangium protrude farther into tl>e cystocarpic cavity 

 than in the other form, but that is not an essential difference. The 

 spores themselves resemble those of Choreocolax Polysiphonice in 

 shape, but are much smaller. Galaxaura was also examined, and an 

 even closer resemblatice seen. The cystocarp of Galaxaura is simple, 

 like that of Choreocolax Polysiphonice, and the spores are larger than 

 those of Chaetangium. The dissmiilarity of the fronds found in the 

 various genera of the Clia^tangiaceic from that of Choreocolax Poly- 

 siphonice can only be considered as a specific distinction, and not as a 

 valid objection against placing the plant in question in this order. 

 The fronds of the forms already included under the Chaetangiaceae 

 are so dissimilar that there cannot be said to be any typical frond in 

 this order. 



Before closing, it seems well to say a few words regarding the 

 methods of work employed in investigating this rather unmanageable 

 alga. The immense amount of gelatinous matter in the frond was of 

 course a most ditlicult thing to preserve properly. Ordinary methods 

 of killing with corrosive sublimate and chromic and picric acids were 

 tried, and yielded partially satisfactory results. The material thus 

 killed was useful for maceration and dissection. All these reagents, 

 however, caused a great amount of shrinkage in the tissues of the 

 plant. Many other methods that seemed suitable were tried with a 

 hope of finding some reagent that would kill the cells and leave them 

 in a natural condition. Nothing was discovered, however, that served 

 this purpose ; in fact, it was found that just as soon as the cells of the 

 plant died, however cautiously they may have been killed, just so soon 

 did they shrink and contract into the grotesque shapes one finds them 

 in. JMore than this nothing could be found that would swell up the 



