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VARIATION 



subject to meristic variation. The general plan is preserved, but 

 wide variation in the details is common, as in the nerve branches 

 from the spinal column. 



The part repeated may be simple, like a digit ; or it may be 

 an entire group, as a whole hand or an entire leg. 



Meristic variation has its seat in cell division. It is of little 

 utility in animals though highly useful in plants, but its phe- 

 nomena are valuable for the insight they afford into the man- 

 ner of variation, the general persistence of plan, and the unit of 

 variability. 



Exercises. Let the student give ten separate examples of 

 meristic variation not mentioned in the text and describe each 

 fully, stating all that is involved of symmetry, homoeosis, etc. 



ADDITIONAL REFERENCES 



VARIATION. A cock with no spurs on the leg, but with well-developed ones 



on either side of the comb. By E. S. Dexter. Science, VII, 136. 

 VEGETABLE TERATOLOGY. By Maxwell T. Masters. 



