|Title||Natural history studies on the earthworms of Michigan|
|Year of Publication||1954|
|Degree||Doctor of Philosophy|
|Number of Pages||282 pp.|
|University||University of Michigan|
|City||Ann Arbor, MI|
1. The objectives of this investigation were to determine: (a) The species of earthworms occurring in Michigan, their distribution, relative abundance, and habitat preferences; (b) The significance of physico-chemical factors of the soil in earthworm distribution; (c) The effects of sessonal cycles of moisture and temperature on earthworm activities and the relationship of these factors to cyclic phenomena apparently inherent in the life histories of the several species; (d) The salient features in the life histories of two earthworm species. 2. Field work began in the fall of 1950 and continued through September, 1953. Field experimentation was initiated in March, 1952, and terminated in June, 1953. 3. 429 new localities records for earthworms were established from fifty counties of the Lower and one county of the Upper Peninsula of Michigan. 4. Eighteen species and one form are now known to occur in Michigan; of these, eight species and one form are herein listed for the first time from the state. Allolobophora minima Muldal has not previously been reported from North America. 5. Maps and checklists are presented giving the distribution of the Michigan earthworms as presently known. 6. A tabular key to the species of Michigan earthworms is included. 7. The habitat preferences, relative abundance, apparent limits of ecological toleration, and the associated species of earthworms, are given where known.