DYNAMICS OF MORPHOGENESIS 



191 



matter of fact, there is no fundamental difference, though there 

 may be a difference in degree between planarians asexually pro- 

 duced and those arising from eggs. The following series gives 

 characteristic results for Planaria maculata. 



Series 51 II and VI. The younger worms (Lot 1) were 3 to 

 4 mm. in length and had emerged from egg capsules in the labora- 

 tory during the last few days preceding the experiment; they had 

 been fed with earthworm once, two days before the test was made. 



The older worms (Lot 2) had hatched several weeks earlier and 

 had been fed with earthworm until they had attained a length of 

 8 to 9 mm. 



Each lot consisted of ten worms. Table 9 gives the data 

 in the same form as the preceding tables. In this series observa- 

 tions were made every fifteen minutes, but since the results at all 

 stages are perfectly uniform and definite, only the alternate 

 readings are given in the table. 



In Lot 1 disintegration begins earlier than in Lot 2 and all the 

 worms are completely disintegrated within two hours after being 



TABLE 9 

 Animals in KCN, 0.001 m. 1.35 p.m., September 1, 1912 



