THE FERN BULLETIN 



25 



sub-species of the plants listed. In this day of studies 

 of variation, such omission is a grave one. In other 

 ways the work seems to have been rather perfunctorily 

 done. The vegetative parts of the ferns are referred 

 to sometimes as leaves and at others as fronds. After 

 a description of the blade of a leaf it is rather discon- 

 certing to see the petiole described as a stipe. In other 

 instances the words fertile fronds and sporophylls 

 are used interchangeably. The work of this first 

 part is by W. R. Maxon and R. C. Benedict in 

 most cases working upon the copious notes left by the 

 late L. M. Underwood. Several new species are de- 

 scribed but not illustrated, a mistake, in the present 

 age of cheap illustrations. It is not likely, however, 

 that the defects we have mentioned will trouble many 

 students for this first part containing only 88 pages 

 bound in paper costs $2.00. 



The family Ceratopteridaceae, or Parkeriaceae, was 

 founded to contain the curious floating fern of the 

 tropics known usually as Ceratopteris thalictroides. 

 By most botanists this fern is supposed to range en- 

 tirely around the earth, and the variation seen in any 

 large collection of the plants is attributed to the diverse 

 habitats in which it is found. Ordinarily floating in 

 brackish or fresh water, it may, by the recession of the 

 waters during drouth, or the action of wind and wave, 

 be left on muddy flats where it may root like other 

 ferns. It has always been a subject for speculation 

 among systematic botanists and different forms have 

 frequently been recognized as good species. The 

 latest, though probably not the last, student to discuss 

 the plant is R. C. Benedict who in Torrey Bulletin for 

 August, 1909, makes four species of it. one of which 



