THALLOPHYTA. 687 



parts of Europe, however (e.g. many upland valleys in Switzerland) this precaution 

 is not taken and the ^oidium-covered Barberries and rusted crops may be seen 

 standing side by side. It is true the rust does not destroy the wheat crop entirely 

 but it seriously diminishes the yield of grain. Long before the life-history of the 

 Rust-fungus had been scientifically traced the Barberry was known to have an 

 evil influence upon cereals. So long ago as 1760 the state legislature of Massa- 

 chusetts passed an Act^ compelling the inhabitants to extirpate all Barberry bushes. 

 The main facts connected with the life-history of Gymnosporangiimi have already 

 been mentioned (cf. p. 522), and the two stages are represented on p. 521. The 

 projecting lobes on the Juniper (fig. 357 1, page 521) consist of masses of teleuto- 

 spores embedded in mucilage. When wetted they swell up, the basidia are pro- 

 duced and the conidia abstricted; the latter are then blown away and, should they 

 alight upon the young foliage of a suitable member of the Pomaceae, penetrate the 

 tissues and produce the JEcidium stage. The efiects of various other members of 

 this group are referred to on pp. 524, 525. Between four and five hundred parasitic 

 Uredinese have been distinguished. 



AuriculariacecB. — Include the well-known Jew's-ear Fungus (Auricularia 

 sambucina) not infrequent on dead branches of the Elder. From its fertile surface 

 basidia with conidia resembling those of the last family are produced, but the 

 basidia are continuous with the hyphse of the Fungus, no chlamydospores being 

 produced 



TremellacecB. — Gelatinous forms found on rotting tree-trunks. Their substance 

 is curiously lobed and plaited; Tremella Mesenterica, which forms large gelatinous 

 orange masses on dead branches, is the commonest of them. 



PilacracecB. — Include a single genus only, Pilacre; it grows on Beech-bark, 

 and consists of a spherical head mounted on a stalk. It is of interest because its 

 basidia (from which the conidia are abstricted) are inclosed in a loose layer of 

 hyphse — the outward continuations of the hyphss upon which the basidia are 

 borne — and it is thought to lead on the family of the Gasteromycetes, in which the 

 basidia are entirely covered in. 



Dacromycetes. — Gelatinous forms resembling the Tremellacese. They approach 

 the Hymenomycetes in that their basidia are destitute of septa. The processes 

 from which the conidia are abstricted are very long. Dacromyces deliquescens is 

 common as a red-coloured tough gelatinous mass on wooden palings. 



Hymenomycetes. — An extensive family characterized by the production of a 



^ The Barberry Law op Massachusetts. — Anno Eegni Regis Georgii II. Vioesimo Octavo, Chap. X. 

 (published January 13, 1755). 



An Act to prevent Damage to £lnglish Grain arising from Barberry Bushes. 



Whereas it has been found by experience, that the Blasting of Wheat and other English grain is often 

 occasioned by Barberry Bushes, to the great loss and damage of the inhabitants of the Province : — 



Be it therefore enacted by the Governour, Council, and House of Representatives, that whoever, whether 

 community or private person, hath any Barberry Bushes standing or growing in his or their Land, within any of 

 the Towns in this Province, he or they shall cause the same to be extirpated or destroyed on or before the 

 thirteenth Day of June, Anno Domini One Thousand Seven Hundred and Sixty. And so forth. (Prom Plow- 

 right's British Uredinece.) 



