—42— 



resented in the Academy herbarium and by others, excellent sam- 

 ples of which she kindly communicated to the writer, are really 

 vigorous forms of P. Calif ornicum Kaulf. Neither does it appear 

 to have been met with by any of the other botanists who have col- 

 lected on this island. Its reported presence must, therefore, be 

 regarded as needing confirmation. 



The case is very different with regard to Guadaloupe, although 

 it was collected by only one of the three botanists who have vis- 

 ited that island. Not only is the identification vouched for by 

 such eminent authorities as Dr. Watson and Dr. D. C. Eaton, but 

 the collector's field-note alone would be conclusive. Dr. Palmer 

 found it V encircling the trunk of a single oak, in a thick mat of 

 moss, and constantly wet by the fogs, covering^the tree with a net- 

 work of its strong, tough roots to the height of ten feet." g 



The fern, then, has reached this solitary island, 600 miles from 

 its nearest continental station and over 300 miles from the nearest 

 authenticated insular station. An inhabitant normally of the 

 Pacific coast life-area, it has intruded far down into the Sonora 

 province. How and when did this migration take place ? For a 

 genuine migration it must have been, since this is not a plant that, 

 in any probability, might have been conveyed fortuitously to dis- 

 tant shores by currents of wind or water, or by birds. 



Geology, perhaps, furnishes an answer. For in the opinion of 

 geologists, these islands are the emergent peaks of a mountain 

 chain, paralleling the present coast line, and connected with it by 

 a broad valley, over which the waves now roll. At that distant 

 time a more moisture-laden atmosphere might easily have induced 

 some northern plants to journey southward along the mountain 

 range. If such emigrants these were, Polypodium Scouleri is the 

 sole survivor. That it is a lingering survivor is indicated by its 

 great rarity, only two among the visitors to the islands having 

 found it, and they, as is shown by their field-notes, each at a single 

 point, and under exceptional conditions, where it probably awaited 

 impending extinction. 



San Bernardino, Cal. 



*j Watson, S. Proc. Am. Acad , 11:120. See also Eaton, D. C, in Watson, 

 Bot. Grt., 2:355. 



— The Torrey Botanical Club has begun the publication of a 

 second monthly journal named Torrey a. Dr. M. A. Howe is 

 editor. 



