THE EXOPERIDIUM OF BOVISTA. 



I found in the park at Upsala some specimens of a young "puff 

 ball" that at first puzzled me considerably. It had a thick, smooth 

 exoperidium, about 700 mic. thick, and composed of large, globose 

 cells (parenchymatous tissue) 30-35 mic. in diameter. Our figure 



271 shows a specimen with the ex- 

 operidium partially cut away, ex- 

 posing the inner peridium. 



I knew no "puff ball" with such 

 an exoperidium, but a miscroscopic 

 examination showed the peculiar cap- 

 illitium of a Bovista, and then I rec- 

 ognized it as young specimens of Bo- 

 vista nigrescens, the only puff ball 

 it could possibly be. I am quite fa- 

 miliar with mature specimens of Bo- 

 vista nigrescens (and also the anal- 

 ogous Bovista Pila of America), and 

 no sign of an exoperidium in seen on 

 the mature plant. What becomes of 



it? It certainly does not peel away in patches as does the exoperid- 

 ium of a Catastoma, or patches of it would sometimes remain. There 

 can be but one explanation. It disappears in ripening, I think, by 

 a process of deliquescence, the same as many of the cells of the gleba 

 do. Morgan suggested this to me years ago, but I never fully be- 

 lieved it until now. The account of the peridia of the genus Bovista, 

 as found in Myc. Notes, page 114, is entirely wrong. 



This deliquescence of the exoperidium of a Bovista explains other 

 things not correctly interpreted before. Thus, the scurfy particles 

 often noted on the common Bovista plumbea are due, no doubt, to 

 imperfect deliquescence. The rare and little known Bovista tomen- 

 tosa of Europe and Australia (cfr. Myc. Notes, page 392) when 

 young has an exoperidium covered with small spines, and when old 

 is as smooth as a billiard ball. Deliquescence alone, I think, can 

 explain that, for if the spines shriveled up and fell away (as they 

 do in the genus Lycoperdon), traces of them would surely remain. 



PHALLUS INDUSIATUS. As is well known, this is the most common 

 phalloid of the tropics and grows in perhaps every warm country of the world. 

 S. Hutchings, of North Bengal, India, writes me it is the only phalloid he 

 notices and that it is plentiful during the rainy season in May and June. I 

 recently met at Kew Mr. C. B. Ussher, who has sent me a number of specimens 

 of this same species from British East Africa. He is a botanist for a rubber 

 company and is located in dense forests where only a few years ago pygmy 

 natives were the only ones to be found. He tells me that this phalloid usually 

 grows in swampy places in the depths of the forest. It is the first time I have 

 known of this species favoring swampy ground. 



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