i 4 4 TEXT-BOOK OF FUNGI 



MacDougal and Lloyd have investigated the members 

 of Monotropaceae, a group without chlorophyll, and find 

 the symbiosis between fungus and host to be very perfect, 

 and evidently of ancient origin. As a result the shoots 

 and roots show much degeneration. 



In many instances the hyphae of endotropic mycorrhiza, 

 on entering the cell of a host-plant, go direct for the 

 nucleus, which finally becomes surrounded by a coil of 

 hyphae. Groom observed this in T/iismta, and considered 

 it as due to chemotropism. 



In the majority of instances the hyphae forming mycor- 

 rhiza have not been connected with any specific fungus. 

 Wahrlich, however, has proved that in certain orchids of 

 the genus Vanda, the hyphae belong to species of Nectria. 

 Elaphomyces forms mycorrhiza on conifers. Members of 

 the Oomycetes, Pyrenomycetes, Gasteromycetes and Basi- 

 diomycetes are known to form mycorrhiza. 



Trent and Bruchmann consider the fungus found in 

 Lycopodium to be a species of Pythium^ and Rees found 

 the fungus on conifer roots to belong to the genus 

 Elaphomyces. 



A very remarkable instance of symbiosis has been shown 

 by Freeman to exist between fungus hyphae and Lolium 

 temulentum, L. perenne, and Z. italicum respectively. In 

 the first mentioned the yearly life-cycle is completely 

 known ; in the remaining two this is not the case as yet, 

 but presumably the departures from that of the known case 

 are not marked. In commercial mixtures of the grains of 

 Z. temulentum^ from eighty-five to ninety-eight per cent, 

 of the total number show a layer of hyphae in the hyaline 

 layer just exterior to the aleurone cells. Along the groove 

 of the grain hyphae are wanting except at the very base 



