436 DIE PROTROPHIE. E wing's list. Probably many of these are correct, but from the station given for Viola lactea Sm., one is tempted to suggest whether such a form of V. canina as passed for '* lactea " at Yarmouth may not rather be the plant. I believe one error has crept in, i.e. " Sium latifolium West Kilbride " ; the authority given knows nothing of that plant having been gathered there, and specimens I have seen thence are a large state of S. erectum [S. angustifolium). Is Scrophlularia umbrosa so common in Ayr? " Mentha pratens is Sole " probably means M. gentilis L. An interesting note on Salix herbacea L. is worth quoting: "It has two sets of leaves during the season, the first set loaded with galls, the second set entirely free from them. If it were not for the second set, it would certainly cease to exist in a short time." I suppose this must be a local habit ; or is such a fact generally known ? " Car ex ovalis var. bracteata Syme. This is not a good variety, as both kinds are found springing from the same root, still its long bract gives it a very different appearance from ovalis.'" One is greatly puzzled to know what Sparganium acutifolia is. Mr. Smith puts no authority after it. Is it a new species ? if so, there is no description. As the other species are duly credited with authorities, it would seem that the above must be the explanation. Potamogeton fili- formis Pers. is recorded from Ardrossan. I have seen P. flabellatus (not so recorded here) from that place ; but of course filiformis is not unlikely to occur, though a critical plant to determine. P. zosterifolius Schum. is recorded, ; if this is correct, it is a notable addition, as the species is only known to occur in Forfarshire : Dr. White was never able to confirm the Perthshire record, though the species was diligently sought by the late Mr. Sturrock. Here and there the author gives the names of moths and butterflies whose caterpillars feed on the various species. He does not confirm one interesting species, i.e., Corallorhiza innata, re- ported in the British Flora from " sandy places near the sea, by Irvine, Mr. Goldie " ; in the first edition it reads, " sandy places near the sea close to Ayr, Mr. Goldie." Mr. Watson, though he accepted the record in Cybele Britannica, doubted it in Topographical Botany. ^ ^ Die Protrophie, eine neue ebensgemeinschaft in ihren auffdlligsten er- scheinungen. Von Arthur Minks. Berlin (Friedlander & Sohn). 1896. In one of his former works on the morphology and biology of lichens, Dr. Minks has described amongst these plants a form of symbiosis, to which he gives the name of *' Syntrophie." He believes that many of the species of lichens as we now know them are the result of an association, in this form of symbiosis, of two or more distinct species. In the present work he states that there occurs amongst lichens yet another form of symbiosis, to which he gives' the name of *' Protrophie." The results of " Protrophie" are very similar to those of " Syntrophie," but while in the latter case the symbiosis is a permanent one, in the former the symbiosis only
