1902] CURRENT LITERA TURE 465 



injury often regenerate, and organs of no value often replace valuable organs 



that were lost. Natural selection, he thinks, could not at once cause a lost 



organ to be perfectly restored, yet only a perfect restoration would be of any 



value. Teleological and vitalistic viewpoints are not looked upon with 

 especial favor. 



K. GoEBEL(BioL Centrabl, 22:385-397,417-438,481-505, 1902) has been 

 stimulated by the recent work of Morgan and Driesch to present the present 

 conditionof ourknowledge concerning regeneration in plants. He cites certain 

 ferns in which regeneration occurs in the normal life history, while there are 

 other cases in which a stimulus is necessary; the former live in moist, the 

 latter in dry situations. In Bryophyllum the latent leaf buds commonly 

 develop only when the leaf has fallen to the ground ; if the midrib be cut, 

 they develop while still on the parent plant. So too the removal of the stem 

 buds causes the leaf buds to develop. Goebel thus thinks that there is a 

 correlation beween the stem and leaf buds, 'the latter being normally 

 inhibited from lack of food. If all leaf buds are removed, new primordia 

 {Anlagen) appear at the leaf base. Other plants in which leaf buds occur 

 are cited, Goebel has also worked on young plants of Cyclamen, a genus 

 which was shown by F. Hildebrand in 1898 to have remarkable powers of 

 regeneration. Hildebrand found that if the blade of the first leaf were 

 removed, a kidney-shaped wing, resembling the lost leaf, was regenerated 

 on each side of the petiole, and at the cut surface. If part of the blade is cut 

 It is restored much as in animals ; if the cut is made down on the petiole, the 

 regenerated leaves may have stalks. If the young tuber is cut, leaves develop 

 around the cut edge. An interesting summary is given of botanical litera- 

 ture dealing with regeneration. 



Other papers on regeneration may be briefly noted: E. Heinkicher, 

 also J. Palisa (Ber. Deutsch. Bot. Gesell. 18: 109-121, 398-410. 1900) have 

 studied regeneration in Cystopteris. Palisa found that any epidermal cell in 

 the bulbil leaves can regenerate a bud capable of becoming a new plant. 

 H. Winkler (Jahrb. Wiss. Bot, 35:447-469. 1900) has studied Bryopsis, 

 which years ago Noll found to display a reversal of polarity. Noll ascribed 

 this to the influence of gravity, but Winkler has shown that light is the deter- 

 niining factor. He suggests that the best nourished parts regenerate stems 

 and the most poorly nourished parts rhizoids ; the migration of chloroplasts 

 toward the light may thus be the decisive factor in the case. Winkler 

 regards the development of rhizoids at the stem pole as a case of heteromor- 

 phosis — the first noted in plants. This author also holds that a number of 

 plants regenerate from the cut surface, rather than from buds, exactly as in 

 animals. — F. Noll (Ber. Deutsch. Bot. Gesell. 18:444-451- iQ^o) accepts 

 Winkler's view that light is the leading factor, but thinks that heteromorphosis 

 has been known in plants though not distinctly claimed.— H, Winkler (Ber. 

 Deutsch. Bot. Gesell. 20:81-87. 1902), as well as Hildebrand and Goebel, 



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