298 STUDIES OF AMERICAN FUNGI. 



Helvetia esculenta Persoon (Gyromytra esculenta), particularly in old 

 or decaying specimens. It has been studied and named by Boehm. It 

 is quite soluble in hot water, and in some localities this species of Hel~ 

 vella is always parboiled the water being thrown away before it is 

 prepared for the table. It seems to be quite generally agreed that 

 young and perfectly fresh specimens are free from the poison. As 

 the poison is very violent, however, this plant should be carefully 

 avoided. 



The symptoms resemble in a very marked degree those of the 

 deadly phallin, the dissolution of the red corpuscles of the blood being 

 one of the most marked and most dangerous ; this is accompanied by 

 nausea, vomiting, jaundice, and stoppage of the kidneys. There is 

 no known antidote for this poison, hence the little that can be done 

 would be similar to that mentioned under phallin. 



When poisoning by mushrooms is suspected, one cannot too 

 strongly urge that the services of a competent physician should be 

 secured with the least possible delay. 



CHAPTER XXIII. 



DESCRIPTION OF TERMS APPLIED TO CERTAIN 

 STRUCTURAL CHARACTERS OF MUSHROOMS. 



By H. HASSELBRING. 



In fungi, as in higher plants, each organ or part of the plant is 

 subject to a great number of variations which appeal to the eye of 

 the student, and by which he recognizes relationship among the 

 various individuals, species, and genera of this group. For the pur- 

 pose of systematic studies of mushrooms or even for the recognition 

 of a few species, it is of primary importance to be acquainted with 

 terms used in describing different types of variation. Only a few 

 of the more important terms, such as are employed in this book, 

 together with diagrams illustrating typical cases to which they are 

 applied, will be given here. 



The pileus The pileus or cap is the first part of a mushroom which 

 attracts the attention of the collector. It is the fleshy fruit body of 

 the plant. This, like all other parts of the mushroom, is made up, 

 not of cellular tissue as we find it in flowering plants, but of numer- 

 ous interwoven threads, called hyphx, which constitute the flesh or 

 trama of the pileus. Ordinarily, the filamentous structure of the 



