24S TllK AMKKU'AN MDNTllLV IS.'pl., 



imsliinj: tln' ii'lls ;i|iart a little and inscrtiim itself rarlhcr and 

 further from the jioiiit whenco it started. 'Vhv liy|il\M' are 

 ftirnislu'd with minute suctorial organs. These are eilled 

 "!>austi>ria"" ( Fiir. 15 h). They are j^lohular swellings of the 

 sides of the hyi>ha. They ]»ush through the et'll-wall and are 

 tlius direetly surrounded with the livinj; jirotoplasin of the host. 

 It is through the haustoria that the parasite does the injury 

 whieh it inflicts, as well ashy the presence of the myceliutn in 

 any of the orjians of the host. An examination ofits lloral orj^ans 

 will often demonstrate the ])resence of the mycelium in thes(! 

 delicate and very im|tortant parts of the host. The fructifying 

 orjians of Cyst»)i>us are of two sorts. There are first and more 

 commonly the aerial hypha' and their conidia. These are 

 formed on hyplia- which burst throufjh the sides of the host giv- 

 ing rise to the blisters or scales already referred to. The conidia 

 germinate on the surface of the host, and send down a hypha 

 through the stoma among the intercellular spaces of the host to 

 reach the succulent cells below. The second mode of develop- 

 ment is the sexual one. It is a similar mode to the conjugation 

 of Mucor. In it. two sorts of cells are formed on hy|»h:r located 

 among the mycelium. One of these is smaller than the other. 

 It is called the antheridia. It is the male element in the sexual 

 process. The other cell is larger and spherical. This is met 

 in the host tissues by the antheridium and the two fuse as 

 shown in Figure 15. The ]»roduct of this act is a cell (tailed 

 the oosphere. The oosphere is now said to be " fertili/x'd," and 

 it now developes into motile swarm-spores like those of the 

 conidia in appearance. These recjuire the death and decay of 

 the host to enable them to develop and jiroduce their genera- 

 tion. 



4. — Other Fungi. 

 It is not within the sco)»e of this article to do more than to 

 awaken an interest in these very easily accessible microscoi)ical 

 subjects. It is worth while, however, in closing, to say that 

 these little beings, are from their immense productivity and the 

 power of drawing their sustenance from other animals and 

 plan t>^, Ciipable of being of great service or harm to man. In 

 the case of the fungi, a majority are probably harmful rather 

 than useful. There are the rusts, the moulds, the smuts, which 

 annually do immense harm to crops; then, there is a fungus 



