118 THE MICIIOBCOP:^. Auir. 



»• 



with it there were other forms, notably filaments of 

 Stigonema and Dicothrix." 



Not arriving at a satisfactory conclusion respecting 

 the first, Mr. Murray referred the matter to M. (romont 

 as final authority, who reported that, " the interior of 

 the calcareous mass is formed of entangled filaments; 

 they appear to belong to a Schizothrix, but which ?" 

 Finally he says, " I do not think one can make anything 

 very distinctly out of this specimen except Schizothrix 

 fasciculata, which undoubtedly occurs in abundance." 

 Excellent figures of this plant are given by Mr. Murray. 



It would thus appear that from two independent 

 sources we have results which, while agreeing in many 

 respects, fail to agree as to the character of the dominant 

 plant, and the idea derived from the observations of Dr. 

 Farlow and myself, that there is no element of constancy 

 in the composition of the flora of these pebbles, beyond 

 the fact that two or three species are in excess, would 

 thus seem to be greatly strengthened. 



Apart from the species found in the pebbles, but Avhich 

 could hardly have played any part in their original for- 

 mation, it will be seen that there are present two and 

 perhaps three species which, by their concurrent growth, 

 may have produced them. It would be of great interest 

 to know whether these large concretions are due to the 

 growth of a single species, or, if to the combined growth 

 of several species, the relative part which each plays. 

 It is, therefore, to be hoped that some observer will 

 watch the locality and obtain quite young material which 

 alone will afford the means of settling this interesting 

 question. — Botanical Gazette. 



General Index. — This General Index is received with 

 very much pleasure by the subscribers. Dr. R. H. W. 

 says : "It is excellent, and evidently cost youa great deal 

 of labor, it adds greatlv to the value of the set of 

 books." 



