294 BOTANY. 



bodies pycnidio-spores. Neither the spermatia nor the 

 pycnidio-spores have been known to germinate ; but from 

 the resemblance of the former to those of Cucurlitaria, 

 Valsa, and other genera of this order, which have been seen 

 to germinate,* it is quite certain that they, at least, are 

 reproductive, and that " they are the agents for the dissem- 

 ination of the species to a great distance," for which they are 

 fitted by their extreme minuteness. In all probability the 

 pycnidio-spores have also a similar function. 



389. — No sexual organs have as yet been observed. 

 Doubtless they exist in the dense tissues of the knot, and 

 fertilization probably occurs in the spring or early summer, 

 while the conidia are being produced on the surface of the 

 young knot. 



390. — The hyphae of each year's knot generally penetrate 

 downward some centimetres into the uninjured bark, and 

 remain dormant there until the following spring, when they 

 begin the growth which results in the production of a knot, 

 as described in paragraph 386. 



(a) Tlie Pyrenomycetes include a large number of exceedingly in- 

 jurious fungi ; they often attack and destroy not only plants, but also 

 insects, upon which their ravages are in many cases very great. 



(6) The classification is as yet in great confusion.f The principal 

 genus is Sphmiia, which contains many species. Valsa, Diatjype, ani 

 Hypoxylon are other important genera. 



(c) Good specimens of Glaviceps purpurea may be obtained from 

 almost any rye-field, and more certainly from the isolated bunches of 

 rye growing here and there in many fields. By making repeated ex- 

 aminations soon after tlie flowering of the rye the conidia may be 

 obtained ; and by gatliering the sclerotia and burying them in moist 

 sand under a bell-jar, tlic receptacles may be grown. 



(d) Specimens of SpJiatria moriosa for study should be gathered at 

 different times in the season — from early spring to the latter part of 

 the winter following. The first gathered will be necessary to the 



* Dr. Max Cornu, in " Annales des Sciences Naturelles," Sixth Series, 

 Vol.' III., gives the details of his experiments upon germinating the 

 spermatia of many Pyrenomycetes. A translation appeared in " Gre- 

 villea," 1877 and 1878, Nos. 36 to 39. 



■f Tlie student may profitably consult, in studying this diflScult order, 

 the finely prepared sets of " North American Fungi," by J. B, Ellis, 

 begun in 1878, and still continuing. 



