82 



THE AMEBIC AN NATURALIST 



[Vol. XLII 



most important being those of Schlotterbeck, 4 Engel- 

 mann 5 and Moquin-Tandon. 6 Since the middle of the 

 last century numerous smaller papers on teratological 

 subjects have appeared. The earlier data have been col- 

 lected by Masters 7 and by Penzig, 8 in the former publica- 

 tion the abnormalities being arranged according to kind, 

 in the latter under the various families, genera and 

 species. 



The main point of interest in abnormal forms lies not 

 in the mere fact of the existence of the abnormalities nor 

 in the extremes which they may reach, but rather in the 

 light thrown by them upon plant development, 9 and they 

 are therefore entitled to equal consideration with hybrid- 

 ization 10 which, as de Vries 11 has pointed out, permits the 

 analysis of the specific characters and thereby makes pos- 

 sible the study of a single character, since the plant is to 

 be considered merely as an expression of the reaction of 

 elementary units, sometimes occurring singly, at other 

 times in groups. 



Among the plant monstrosities which are most fre- 

 quently observed are fasciations, in which more often the 

 stems, but sometimes other parts of the plant, appear to 

 broaden and assume a flat appearance. Their existence 

 has been known for centuries, for instance the fasciation 

 of Sedum reflexwn (8. crispum), illustrated by Munting 12 



4 Schlotterbeck, P. J. Sehediasmn botaiiicum do monstris plantarum quo 

 analogiam regno vegetabili cum animal! intercedentem in producendis 

 iisdem adstruit et figuris fflnstrat. Acta Helvetica, 2: 1, 1816. 



5 Engelmann, G. De Antholysi Prodromus. Frankfurt a. M., 1832. 



6 Moquin-Tandon, A. Elements de Teratologic Vegetale. Paris, 1841. 



I Masters, M. T. Vegetable Teratology, London, 1869. 

 s Penzig, O. Pflanzen Teratologic Genua, 1890-1894. 



•Goebel, K. Bedeutung der Missbildnngen fur die Theorie der Organ- 

 bildung. Organographie der Pflanzen, 173, 1898-1901. 



» Tschermak, E. The Importance of Hybridization in the Study of De- 

 scent. Eeport of the Third International Conference on Genetics. Royal 

 Horticultural Society, 278-284, 1906. 



II de Vries, Hugo. Intracellulars Pangenesis. Jena, 1889. Sur les 

 unites des characteres specifiques et leur application a 1 'etude des hybrides. 

 Rev. !>en. hot., 12: 257, 1900. 



"Munting, A. Waare Oeffeninge der Planten, 1672. 



