20 PROCEEDINGS OF THE ACADEMY OF [1885. 



The deaths of Thomas Clyde, a member, and of Friedrich Ritter 

 v. Stein, a correspondent, were announced. 



The following minute was adopted : 



The Academy of Natural Sciences of Philadelphia learns with 

 profound regret of the death of Prof. Wm. Wagner, one of its 

 earliest members, whose generous encouragement of scientific 

 pursuits has done much to foster a study of the natural sciences 

 in this country. 



Observations on Tenacity of Life, and Regeneration of Excised 

 Parts in Lumbricus terrestris. — Miss Adele M. Fielde remarked 

 that the observations recorded before the meeting held Jan. 6, 

 were made in the laboratory of the Academy of Natural Sciences 

 of Philadelphia. The temperature had been nearly constant at 

 about 60°, and varied only from 55° to 65°. The observations 

 began Nov. 29, 1884. No worm lived more than a few hours when 

 exposed to the air. Worms kept in water, without food, the 

 water changed daily, lived from eleven to fourteen days. It 

 made no apparent difference in the duration of life, whether the 

 worms were kept in darkness or in light. 



Eight portions of worms, consisting of from twentj' to thirt3 r 

 segments, taken from the posterior end, had lived in earth during 

 the forty days of observation, and though plump, healthful, and 

 with blood of its usual redness, showed no signs of growth at 

 either end. Between the segments, however, new half-segments 

 had been inserted, after a method which ladies in sewing call a 

 gusset. Some of these worms had five such insertions, w r hile no 

 similar half-segments were observed in many worms that were 

 examined, in order to ascertain whether such half-segments 

 existed in whole and healthy worms. These new half-segments 

 appeared at irregular distances apart, between the old seg- 

 ments, on the sides of the portions of worms, and appeared to be 

 a manner of growth not heretofore observed in earthworms 

 regenerating exsected parts. 



Nine worms from which the five anterior segments were excised 

 Nov. 29, had been kept in moist earth, with which comminuted 

 leaves of oak and maple were mingled. The brain of the earth- 

 worm lies in the third segment, and the first suboesophageal 

 ganglion in the fourth segment, so that the brain and oesophageal 

 collar were removed by the excision. All these worms were 

 living, and a part of them had wholly regenerated the excised 

 segments. 



Ten worms, which at the same date lost five anterior and from 

 twenty to thirty posterior segments, were all alive and were 

 regenerating the excised portions. 



Eight worms, which at the same date lost their posterior seg- 



