540 



PAET IV. 



VITAL ACTIONS OF THE LOWER FUNGI. 



The vital HAVING discussed the conditions necessary for the 

 life of the fungi with special reference to the nutrient 

 materials which must always be present in their sur- 

 roundings, it is the ohject of this part of the work to 

 show how the nutrient materials are taken up, the trans- 

 formations which they undergo in the body of the 

 organisms, in what manner growth takes place, and how 

 the energy, which is necessary in order to enable the 

 fungi to carry out their other functions, is obtained 

 from transformation of the material. It is evident that 

 this subject, which has also to do with, and to explain as 

 far as possible, the special activity of the fungi in ex- 

 citing fermentation and disease, forms one of the most 

 important chapters on the subject of the fungi. 



Proposed plan The tissue change and development of energy of the 



of treating the , . . r . ,, . QJ ,. , 



subject. mould, yeast, and fission fungi agree in their essential 



points to such an extent that it has not appeared 

 necessary to treat of the three classes separately in this 

 chapter. The behaviour of the fission fungi, as being 

 the most important group from a hygienic point of view, 

 is taken as a groundwork, and it is only at certain 

 places that attention is specially directed to differences 

 in the behaviour of the other chief groups. 



In the first place, we shall make a short general review 

 of the tissue change and development of energy of the 

 lower fungi, closely following what is known as to the 

 biology of the higher plants. We must then discuss 

 the individual phases of the vital activity of the fungi, 

 the assimilation of nutrient materials, and the changes 

 which they undergo in the body, the development of 



