only near the ground. When I arrived on the scene the sun was 

 nearly an hour high, and the ice had already begun to melt, 

 which made a more detailed study out of the question. The 

 wings may have been a little larger before sunrise than they 

 were when I saw them. 



The previously recorded frost plants are supposed to be 

 natives where they were found, at various places from New 

 York to Minnesota and Florida (and perhaps the European 

 cases too, though I have not had access to the European litera- 

 ture on the subject). But the Richardia is supposed to have come 

 from the tropics, where one would suppose that it would never 

 have learned to make ice, so to speak; though details of its na- 

 tive haunts are lacking, and it may have come from some com- 

 paratively cool and elevated portions of the tropics. 



More information about the geographical distribution of 

 this phenomenon, and the weather conditions that produce it, 

 would be interesting, though the matter perhaps has no great 

 physiological or ecological significance. The fact that it is rather 

 rare in the experience of any one person would seem to indicate 

 that it occurs only with some exceptional combination of weath- 

 er conditions. The case I noticed in Florida a few years ago 

 occurred on a freezing night after a long rainy spell, and that 

 suggested that the dead or dying plant stems were pretty well 

 saturated with water just before the freeze. But in this latest 

 Alabama case there had been no rain for a week or more, as far 

 as I know. 



In the fall of 1934 a citizen of Albertville, Alabama, wrote 

 to the professor of chemistry at the University of Alabama 

 about having observed the phenomenon near there, and he 

 seemed to have visions of a new process for making ice. Evi- 

 dently it was something new to him; but if he identified the 

 plant or discussed the weather conditions I do not now remem- 

 ber the details. 



It seems that most of the recorded observations of this phe- 

 nomenon have been made in late fall, by persons who had en- 

 countered it but once in their lives; and that would seem to 

 suggest that an individual plant can produce ice crystals only 

 once. However, in Torreya (35:57-59) for June, 1935, Dr. L. M. 

 Dickerson reports a group of plants (tentatively identified as 

 Pluchea) at Lebanon, Tennessee, that exuded ice three or four 



