Francis E. Lloyd — 156 — Carnivorous Plants 



upper ends of the pedicels." In my preparations aggregation, in the 

 generally understood sense, occurred in the upper end of the tentacle 

 stalk. Similar appearances were seen in glands treated with pepsin, 

 and peptone Witte (each i% soln.), in that the first thing noted is the 

 appearance of drops and there is no breaking up of the grand vacuole 

 into parts, as is to be constantly observed in the tentacles. In KH2- 

 PO4 (tried by Coelingh as a component of sahva) in i % soln. the 

 gland cells behaved so far differently that its action can be only doubt- 

 fully compared with that of saliva since vacuoles without pigment are 

 formed which push aside the cell contents, producing a distinctly path- 

 ological effect. Aggregation occurred in the tentacles, but this also oc- 

 curs in water. In order to check on my observation, I took a piece of 

 leaf which had lain in oil for 48 hours, and which showed very clearly 

 that there was no aggregation at all in any gland cells. After removing 

 the oil, which does not adhere to the glands because of the mucilage, I 

 treated it with saliva. In 15 min. droplets had appeared in the lateral 

 cells of the inner course of gland cells (C-II), the epidermis (C-I) re- 

 maining quite clear. At the end of 50 min. all the cells of C-II had each 

 a large drop, appearing in the apical cells last. All the lateral cells of 

 C-I had drops in them, a few small droplets in some apical cells. In 

 an hour's time, droplets had appeared in many of the apical cells of 

 C-I and they were evidently enlarging. 



These observations seem to indicate that during the ordinary course 

 of events when the glands are secreting mucilage the condition of the 

 gland cells may be found in various states such as Homes had de- 

 scribed. If the glands are fed they may follow one of two courses. 

 If the gland cells are filled with smaller vacuoles (are aggregated), these 

 become confluent to form a single large drop, the condensed vacuole of 

 Homes. If the gland cells are in the resting condition, that is, are in 

 the grand vacuolar stage with no sign of aggregation, the course of 

 events on feeding consists in the formation of small droplets in the 

 cells of the inner glandular course in the lateral regions of the gland. 

 This advances till the apical cells of this course have all formed drop- 

 lets. These grow until by their size they form an optically dense layer. 

 In the meantime, droplets have appeared in the epidermis, in the 

 lateral region. This also progresses toward the apex, until all the epi- 

 dermal cells are involved. The drops all contain pigment. In the 

 course of change, the gland becomes denser and darker in color as Dar- 

 win observed. During six hours aggregation had occurred in the tenta- 

 cles and by next morning it had progressed quite to their bases and 

 into the leaf tissue about their bases. 



Whatever the final agreement as to the course of aggregation, which 

 appears to be different in detail, if the same in results, in gland and 

 tentacle, the whole activity is most extraordinary, and demands much 

 further study before any final answer can be given as to the relation of 

 aggregation to secretion and absorption. 



Studies of cytoplasm and nucleus. — The studies of the living cell 

 leading to our knowledge of aggregation led to a desire to know more 

 of those details of behavior of the cytoplasm and especially of the 

 nucleus which cannot be discovered by the methods used for obser- 

 vation of the li\'ing material. Accordingly the method of fixation fol- 



