304 NATURAL SCIENCE [November 



than fourteen species indicates that there is still much to be done 

 before a satisfactory knowledge of the bryology of the islands is at- 

 tained, and Mr Cardot believes that the number (eighty) could 

 easily be doubled. The fungi are practically unstudied, and many 

 species should be found in the moist wooded regions. The list of 

 marine algae, " though unquestionably small, may doubtless be in- 

 creased considerably by collections prosecuted through the entire 

 year, while there is reason to expect a very large number of diatoms 

 and desmids, as well as many representatives of other groups of 

 fresh-water algae, whenever careful collections shall have been 

 made." As regards flowering plants and ferns, though the list 

 is probably nearly complete, there is still scope for much interest- 

 ins work, such as a detailed local flora for the islands, with an 

 analysis of the influences which favour the extended distribution of 

 one species while restricting another to a very limited area. For 

 such an enterprise the catalogue which Prof. Trelease appends to 

 his botanical observations would form a useful basis. Most of the 

 species, it is suggested, " may have been introduced by ordinary 

 means, largely through human agency, since the discovery of the 

 islands, for they are so precisely comparable with similarly named 

 species from other parts of the world as to suggest the lapse of a 

 very short time since their separation from the parent stock." Only 

 a few are peculiar. Some of the latter are limited to one or other or 

 several of the islands ; but the native flora has clearly suffered so 

 much through the inroads of man and domesticated animals, that it 

 is impossible to say whether or not these local limitations have 

 always existed. The greater number of the flowering plants are 

 either wind-fertilised or adapted for pollination by but little- 

 specialised insects, having as a rule open flowers, with readily 

 accessible nectar or pollen. As regards relation between plants 

 and animals, Prof. Trelease remarks that, as there are only seven 

 species of wild mammals found in the islands, and nine endemic or 

 commonly concerned with plant-dissemination elsewhere, and few 

 birds capable of aiding in this work, except for aquatics or marsh 

 plants, " it is scarcely to be expected that special dissemination 

 adaptations would be found on the part of aboriginal plants, which 

 presumably have been associated with these animals for a relatively 

 short time, nor of recently introduced plants, unless the relations 

 have been established and the modifications worked out before 

 either plant or animal reached the Azores." "Well developed burrs, 

 for instance, are found only on recent introductions, and the great 

 majority of species " either have no special modification adapting 

 them to certain dissemination, but depend upon gravitation, the 

 wind, or hygroscopic movements of their seed vessels, or else their 

 adaptations are out of harmony with their surroundings." 



