Francis E. Lloyd — 158 — Carnivorous Plants 



disruption, show hollows and cracks, and appear to be in some vague 

 but perhaps intimate connection with the nucleus, indicating that they 

 are products taken up by it. At the " high point" of feeding the 

 nucleus has enlarged and the membrane becomes less definite and 

 finally disappears so that the chromosomes and nuclear materials ap- 

 pear to he free in the cytoplasm, or at any rate in a nuclear lymph. 

 KoNOPKA observed in the resting stage the bodies which Rosenberg 

 called prochromosomes, but could not confirm his belief that they oc- 

 cur in a constant number, regarding them rather to be of nucleolar 

 nature. After feeding the nucleoli become reduced in size, and lie in a 

 large vacuole (" Hof") from which, in many cases, he could observe 

 canals leading to the cytoplasm, bringing the nucleus into more inti- 

 mate contact with the cytoplasm. Here it is to be regretted that cost 

 prevented the reproduction of his photographs, since the figures are 

 unsatisfactory to a degree, and show no convincing evidence of this. 

 The chromatin on the other hand exhibits increase and occurs in larger 

 masses of various form. After 24 hours they become very evident by 

 their clearness and size, and besides granules of various sizes there ap- 

 pear rod-shaped structures (" Rhabdoids"?) lying near the periphery 

 (of the nucleus) sometimes paired and connected by fibers with the 

 interior of the nucleus, but in no constant number. The nucleolus has 

 now been dissolved, and appears as a pale, rather than, according to 

 Rosenberg, a distinct body. The chromatin rods now unite to form 

 threads and rings. Among them the granules, which Rosenberg 

 thought to be prochromosomes, are secondary nucleoh, indicating 

 enhanced nucleolar activity. They always he in vacuoles (" Hof") 

 and have no connection with the nuclear structure, show disinte- 

 gration and disappearance at the high point of the reaction. During 

 long periods of digestion these events appear not to progress steadily, 

 but rather to pulsate — there is a rhythm in behavior. These nucleolar 

 structures are regarded by Konopka as supplying materials for forming 

 mucilage and for digestion, and he is inchned to regard the central and 

 peripheral nucleoh as having different functions. The whole aspect of 

 the changes in the chromatin and nucleolus indicates that these changes 

 are connected with ferment production. With the escape of the fer- 

 ment the chromatin shrinks in ring forms, so that one might regard the 

 nucleus now as being in a spireme stage, leading to mitosis, or merely 

 as a reformation of chromosomes in a somatic condition. They are at 

 all events true chromosomes. 



It has been attempted to summarize the above work with not 

 too great brevity, so that the reader may appreciate the difficul- 

 ties of interpretation. It is not too much to say that, while it has 

 been shown experimentally that changes in the cell do indeed occur 

 during digestion, and while we have become aware to some extent 

 what, in detail, these changes are, it must still be recognized that we 

 are yet lacking general agreement as to the precise nature of many of 

 these details, and much less are in a position to attribute precise func- 

 tions to the various structures seen. 



Digestion; enzymes. — Darwin (1875) proclaimed the digestive 

 power of the secretion of Drosera tentacles. He fed the leaves proteins, 

 connective tissue, cartilage, gelatin, to find that these were attacked. 



