366 WALTER GARDINER. 



presenting a most characteristic appearance. From a very 

 careful examination of numerous sections it appears to me 

 that in a number of well-defined instances the protoplasmic 

 threads are optically continuous. In other cases union 

 between the contents of corresponding pits appears to be 

 affected by a sieve-plate-like arrangement. Some of the 

 processes on the other hand appear to end blindly, and do 

 not reach as far as the middle lamella. When the proto- 

 plasm has undergone considerable shrinking and a certain 

 tension has thus been brought to bear upon the threads, 

 rupture of the latter frequently occurs, which rupture, how- 

 ever, seldom takes place at the point where the threads 

 cross the middle lamella, but nearly always on one or on 

 both sides of this point. These results appear to point out 

 clearly the intimate connection existing between cell and 

 cell. I am unable to speak with the same certainty on the 

 subject of Robinia, Phaseolus, and Amicia, although the 

 results hitherto obtained are of the most promising descrip- 

 tion. I hope shortly to be able to publish a more detailed 

 account of the whole subject, together with an investigation 

 of the stamens of the Cynaracese and of tendrils, in which 

 latter some indications of the same structure have been 

 observed. 



Botanical Institute, Wuezbukg. 



