CLASSIFICATION AND NOMENCLATURE 139 



c. Cultivation : camnium (ica/ivo), cultivate) 



d. Drainage: ochetium (ox«tos, o, drain) 



e. Irrigation : ardium (opSw, irrigate) 



II. Anomalous successions: xenodochae (itvoi, strange, un- 

 usual) 

 The following series will illustrate the application of this 

 system of nomenclature to particular successions, and their 

 stages, or formations. 



ThIaspi-Picea-sphyriam : pennycress-sprocc talus succession 



Thlaspi-Eriogonum-chalicium: pennycress-eriogonum gravel slide 

 formation 



Elymus-Gilia-ohalicodium : wildrye-gilia half gravel slide for- 

 mation 



Quercus-Holodiseus-lochmodium : oak-fringewood dry thicket for- 

 mation 



Pinus-xerohylium : pine dry forest formation 



Picea-Pseudotsuga-hylium : spruce-balsam forest formation 



Bryum-Picea-pyrium : moss-spruce burn succession 



Bryum-telmatium : moss meadow formation 



Aster-Chamaenerium-poium : aster-fireweed meadow formation 



Deschampsia-Carex-poium : hairgrass-sedge meadow formation 



Salix-Betula-helolochmium : willow-birch meadow thicket for- 

 mation 



Populus-hylium : aspen forest formation 



Picea-hylium : spruce forest formation 

 Lecanora-Carex-hedium ; lichen-carex residuary succession 



Lecanora-Gyrophora-petrium : crustose lichen rock formation 



Parmelia-Cetraria-chalioium : foliose lichen gravel slide for- 

 mation 



Paronychia-Silene-chalicodium : nailwort-campion gravel slide 

 formation 



Carex-Campanula-coryphium : sedge-bluebell alpine meadow for- 

 mation 

 Eragrostis-Helianthus-zerasium : eragrostis-sunflower drainage 

 succession 



Eragrostis - Polygonum - telmatium : eragrostis - heartsease wet 

 meadow formation 



Helianthus-Ambrosia-chledium : sunflower-ragweed waste for- 

 mation 



INVESTIGATION OF SUCCESSION. 



The study of succession must proceed along two funda- 

 mental lines of inquiry. It is necessary to investigate 



