ZYGOMYCETES. 95 



spores are often adapted to germinate in the alimentary canals of 

 warm-blooded animals, have an optimum corresponding to the 

 temperature of these animals, but with a little margin. 



Systematic Division. The lowest class of the Fungi is that 

 of the PHYCOMYCETES, which have an unicellular mycelium, sexual 

 and asexual reproduction, and have doubtless sprung from spo- 

 rangia-bearing, lower Green Alga?. From the Phycomycetes (and 

 certainly from the Zygomycetes) spring two well defined branches, 

 each with numerous distinct species; to the one branch belong the 

 HEMIASCI and the ASCOMYCETES, to the other the HEMIBASIDII and 

 the BASIDIOMYCETKS. Ascomycetes and Basidiomycetes may be 

 united under the title of MYCOMYCETES or HIGHER FUNGI. The 

 Hemiasci and the Hemibasidii constitute the class of MESOMYCETES. 

 The Hemiasci are an intermediate form between Zygomycetes and 

 Ascomycetes ; the Hemibasidii a, similar group between the Zygo- 

 mycetes and Basidiomycetes. Mesomycetesand Mycomyceteshave 

 only asexual reproduction ; sexual reproduction is wanting. Their 

 mycelium is multicellular. 



Up to the present time about 39,000 species have been described. 



Review of the divisions of the Fungi : 



ciass L Phycomycetes (Algal-Fungi). 



Sub-Class 1. Zygomycetes. 

 Sub-Class 2. Oomycetes. 



Family 1. ENTOMOPHTHOKALES. 



Family 2. CHYTRIDIALHS. 



Family 3. MYCOSIPHONALES. 



class ii. Mesomycetes. 



Sub-Class l. Hemiasci. 



Sub-Class 2. Hemibasidii (Brand-Fungi). 



ciass in. Mycomycetes (Higher Fungi). 



Sub-Class 1. Ascomycetes. 

 Series 1. Exoasci. 

 Series 2. Carpoasci. 



Family 1. GYMNOASCALES. -\ 



Family 2. PEHISPORIALES. ? Angiocarpic Exoasci. 



Family 3. PYKENOMYCETES. J 



Family 4. HYSTERIALES 1 TT T< 



* - Hemi-angiocarpic Exoasci. 



family 5. DISCOMYCETES. J 



Family 6. HELVELLALES. Gymnocarpic (?) Exoasci. 

 Additional : ASCOLICHENES. Lichen-forming Ascomycetes. 



