THE AMERICAN BOTANIST 19 



the poison solanine, present. On the other hand those who 

 contend that the fruits are innoxious may have had the other 

 variation in hand. 



Pine Seeds as Food. — To many people in the United 

 States the seeds of the pine seem to have Httle economic vahie. 

 Seeds of the eastern and southern pines are two smah to be of 

 any value but in the southwest are several species with seeds 

 large enough to form an appreciable source of food. In some 

 sections pine seeds may be regarded about as beechnuts are 

 in the New England and Middle States, but in others they are 

 held in considerable esteem. Gathering pine seeds is a recog- 

 nized industry among certain Indian tribes. In South 

 America the Chilian pine or monkey-puzzle tree (Aiirancario) 

 a plant well known in cultivation in greenhouses on this side 

 of the equator, yields a large amount of food. One tree, it 

 is reported, will supply food for a dozen persons. The cones 

 are six inches or more in diameter and each scale encloses 

 two seeds an inch or more long. Since the cones are borne 

 in abundance the pine seed harvest is of much value. 



Growth Rings. — In regard to the growth rings you 

 mention on page 88 of the last volume I have heard what I 

 think to be a satisfactorv explanation, though to what extent 

 proved by experiment I do not know. I refer to the "fairy 

 circles" of basidiomycetes and the explanation applies to the 

 plants in question as much, I think. It will be noticed that 

 the circles are larger every succeeding year and it has been 

 said that the plants use up the humus food proper for them 

 and naturally extending outward as the spores are annually 

 dispersed. Starting from a small patch they pass outward 

 every season because the food supply gives out where they 

 were the preceding year. Of course the spores are spread 

 over the whole lawn but the greatest abundance is found 



