Vol. l] Bovard. — Sense Organs in Microscolex Elegans. - Jsi 



7. In each metamere except those of the posterior end the 

 largest sense organs are found in the median zone, the uexl in 

 the anterior zone, and the smallest in the posterior zone. 



8. The total number of sense organs in Microscolex elegans 

 is less than 15,000, to 150,000 in Lumbricus agricola. 



9. There are no groups of sense organs about the nephro- 

 pores, sexual ducts, or the chaetae sleeves. 



10. The sense organs are the most numerous and the Largest 

 on those parts of the worm which most frequently come in con- 

 tad with surrounding objects. 



11. The ratio of the numbers of sense organs in two given 

 areas is approximately inversely proportional to that of the time 

 reactions. 



I' inn rsity of Oregon, 



Eitt/ciic, Orcijoi). May 11. 1901. 



