CHAPTER I 



SOCIAL ORGANISATION IN COPRINUS STERQUILINUS 



AND OTHER FUNGI 



Social Organisation in Animals and Plants — The Algae — The Myxobacteriaceae — 

 The Acrasieae — The Mycetozoa — The Phycomycetes — The Hymenomycetes — 

 Hyphal Fusions and Clamp-connexions in the Hymenomycetes — Social 

 Organisation in Coprinus sterquilinus — Social Organisation in Other Hymeno- 

 mycetes — Social Organisation in Other Fungi — The Various Functions of 

 Hyphal Fusions in the Hymenomycetes — Sex and Hyphal Fusions in the 

 Hymenomycetes 



Social Organisation in Animals and Plants. — Social organisation 

 is known to exist in a greater or less degree in many animals. It 

 has attained a high state of perfection in certain insects, e.g. the 

 hive-bee, ants, and termites, while in man it has been an essential 

 factor in the progress of civilisation. 



In the Bryophyta, the Pteridophyta, and the Phanerogamia, the 

 individuals of one and the same species, when they come into 

 contact on the same substratum, always compete with one another ; 

 and, in these great plant phyla, there is no species known in which 

 neighbouring individuals become united in such a way that some 

 only of the individuals produce spores or seeds while others remain 

 sterile, the former reproducing the species at the expense of the 

 latter. Where in certain trees actual fusion takes place between the 

 roots or stems of adjacent individuals which happen to come into 

 contact (Figs. 72 and 73), the fusions appear to be of but little 

 physiological importance and they do not lead to any division of 

 labour between the individuals concerned. 



In some of the Thallophyta, namely, certain Algae, the Myxo- 

 bacteriaceae, the Acrasieae, the Mycetozoa, and certain Fungi, the 

 individuals of one and the same species become associated so as to 

 form remarkable social communities. 



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