186 THE AMEttldAtf MONTHLY [June; 



period affords ample evidence of the presence of parasitic 

 fungi belonging to tlie primitive type indicated above. 

 Neither do the members of the animal kingdom alto- 

 gether escape, unmistakable evidence of the presence of 

 parasitic fungi in the remains of ancient corals having 

 been recorded ; and even at the present day various 

 species of insects serve as hosts for highly evolved types 

 of fungi. 



In one of the earliest groups of terrestrial fungi, the 

 Peronosporeas, the evolution of a second form of repro- 

 duction was perfected, known as the conidial or summer 

 form of fruit. The ancestral sexual fruit produced in 

 the tissues of the host was retained without modification. 



The conidial form of fruit is developed as follows. The 

 members of the Peronosporea? are parasitic on living 

 plants, attacking more especially the foliage ; the vege- 

 tative mycelium remains inside the host, and after rami- 

 fying and accumulating an amount of reserve material 

 gives origin to immense numbers of specialized branches, 

 which either push through the epidermis or through 

 the stomata into the air, and there produce myriads of 

 conidia asexually formed,very minute reproductive bodies. 



The object of producing conidia outside the host was 

 for the purpose of utilizing the available terrestrial means 

 of spore dissemination. In early times wind and rain 

 would be the dispersive agents, and with the advent of 

 groups of insects having a taste for nectar or being at- 

 tracted by brilliant colors, we find groups of fungi, as 

 some of the Ascomycetes — Claviceps, /Sclerotinia, etc. — 

 and all the Phalloidese, offering the attractions of nectar, 

 smell, and brilliant colors in various combinations, for 

 the purpose of effecting through the unconscious agency 

 of insects the diffusion of conidia. 



The conidial phase of reproduction in most fungi cor- 

 responds to what are popularly known as moulds and 

 mildews, and all such were at one time considered as dis- 



