I] . SAPROPHYTISM 9 



spore masses; later, if it is eaten by some herbivorous animal, the spores 

 pass uninjured through the alimentary canal and germinate while still in the 

 intestine or on being ejected with the dung. In some cases the wall of the 

 spore seems to have become so effectually adapted to resist injury during 

 its passage through the animal that it is incapable of either stretching or 

 cracking as a preliminary to germination except after digestion or some 

 other special treatment. 



Thus de Bary succeeded in germinating spores of species Pilobolus and 

 Mucor in water and those of Sordaria and Coprinus in nutrient solution, by 

 exposing them to a temperature between 35° and 40° C; Massee and Salmon 

 obtained germination in the spores of Ascobolus perplexans,, and A. glaber, 

 after about 20 hours in either tap water or dung decoction, at a temperature 

 of about 27° C. ; I found that spores oi Lachnea stercorea germinated in an alka- 

 line medium (preferably dung decoction) after incubation for several hours 

 at 38° C. (the temperature of the body of the cow), and Welsford succeeded 

 by the same means in germinating the spores oi Ascobolus furfuraceus, and 

 Cutting those of Ascophanus carneus. Ramlow, however, describes the ger- 

 mination of spores of the last named species at room temperature in twenty- 

 four hours. Further, Dodge was able to germinate the spores of several 

 Ascobolaceae on dung agar by exposing them for 5 or 10 minutes to a 

 temperature of 50° to 70° C, and Ramlow germinated those of Ascobolus 

 immersus by sowing them on agar which was still hot after sterilization. In 

 certain cases the action of direct sunlight was found by Dodge sufficient to 

 induce a moderate percentage of germinations and to raise the temperature 

 of the liquid containing the spores to about 50° C. in half an hour. 



Finally, as I am informed by Mr Ramsbottom, germination may be in- 

 duced mechanically by cracking or breaking the epispore, for example by 

 rubbing the spores between two coverslips, so that all the above methods 

 are a mere variety of means towards this end. 



In the case of Lachnea stercorea, spores incubated for 18 to 40 hours, 

 either in a succession of digestive fluids, or in dung extract, only germinated 

 approximately 50 hours after the beginning of the experiment. It is probable 

 that they do so in nature about two days after being swallowed. In Asco- 

 phanus carneus, also common on cow dung, germination is much more rapid, 

 taking place under similar circumstances in a single night, so that the spores 

 under natural conditions may be inferred to germinate while actually in the 

 intestine. Further development, however, is in all cases dependent upon the 

 fungus reaching the exterior of the mass of dung. 



In Coprinus sterquilimis, Baden found that not only warmth and an alka- 

 line medium (aqueous extract of horse dung), but the presence of certain 

 bacteria also was necessary for germination. Appropriate bacteria may 

 sometimes be a factor in the development of the ascocarp (Molliard) and 



