8o 



POTTS 



As to its method of multiplication or reproduction ; it is 

 most important to call attention to a singular, apparently a 

 unique habit that ma}' be called its asexual germination, by a 

 species of subdivision , — neither longitudinal nor transverse, but 

 partially lateral, caused by the budding out and eventual sepa- 

 ration of a portion of the middle-third of the body. This is 

 shown highly magnified in Figure 6, carefully drawn by Dr. 

 J. A. Ryder from longitudinal sections of his own cutting. 

 This figure, probably better than any words of mine, may 

 explain itself. It must be told, however, that the notches that 

 may be seen to originate at each end of the swollen portion, 

 rapidh^ deepen, and eventually join, near the lower extremity. 

 The progress and final result of this constriction I have tried 

 to show by the diagram. Figure 7, when the asexual larva is 

 represented as growing and finally liberated in the condition 

 above described. 



The verity of the second and higher sexual method of 

 reproduction in Microhydra, by the budding, development and 

 liberation of true uiednscr, I hold to be well established by the 

 discovery among my papers of Figure 5, the original of which, 

 dated September 5th, 1897, represents a bicapitulate hydroid 

 with its pedal-disc : bearing also a budding medusoid at an 

 early stage of its development. The interest was increased 

 when I read in my letter-copying book the following extracts 

 from a letter dated two days later : — 



" Most important was my success in removing a swelling- 

 bud to the stage of my microscope, where its connection with 

 the stem of one of a colony of two hydroids was unquestion- 

 able. The pKp, of course, grew faster than his daddy, who 

 curled his head to one side in evident disgust ; the pedicle of 

 the medusa-bud assuming the position of the main stem. I 

 made a rude camera lucida sketch at the time. ( Figure 5 ). 



" On the following morning I was pleased to see that deve- 

 lopment had gone on unchecked by its removal. When 

 examined that evening the tentacles had been projected to 

 near!\- their full length, the expansion and opening of the 



