AN ANOMALY OF WHEAT ANTHERS 



S. A. Anthony, Chicago, III. 



OX a head of wheat grown in a 

 ^^reenhouse of the United States 

 I )ei)artinent of Agriculture, at 

 Arlington, Virginia, an interest- 

 ing anomaly of the anthers was ob- 

 served, which, as far as the writer 

 knows, has not been previously reported. 



The literature of teratology is very 

 large, especially the observation of cases 

 of metaniori)hosis of anthers into petals 

 in coniposite llowers, and in the trans- 

 formation of the integuments of the 

 ovary into leaves. Teratologic phe- 

 nomena in plants may arise from dif- 

 ferent causes. The usual consequence 

 is the metamorphosis of a sexual organ 

 into a vegetative one. Whether these 

 are of pathologic or physiological origin, 

 the cause can hardly be separated from 

 a physico-chemical stimulus of the pro- 

 toplasm arising from the production or 

 liberation of substances (hormones) 

 which produce the metamorphosis. 



According to Goebel, the stamen of 

 the Gramineae (Goebel, K. Verglcich- 

 ende Rntwicklungs geschichte der 

 Pflanzenorgane, p. IIS; Goebel K. ( )r- 

 ganographie der Pflanzen, 10 1:!. ]>. 

 329) is a sporophyll originated by the 

 transformation of a primordium (./;/- 

 I age) of a foliage leaf. It produces the 

 microspores, and before the appearance 

 of the spore-forming tissue is a four- 

 angled body, in every angle of which a 

 sporangium is dififerentiated. The two 

 pollen-sacs with the filament form the 

 anther, being united by the connective. 



In Phyllody the stamens are trans- 

 formed either to foliage leaves or to 

 petals. Goebel (loc. cit.) explains this 

 through the action of the factors which 

 cause the transformation of the leaf 

 primordium into a petal, on the primor- 



dium of the stamen, causing the sporo- 

 phyll to transform before the formation 

 of the pollen-sacs. 



In a case coming under the notice of 

 the writer, however, only half of the 

 sporophyll was transformed, and not 

 into a leaf or a petal, but into a process 

 bearing stigma hairs. As can be seen in 

 Fig. (J, one-half the anther tip is 

 transformed into a stylus with stigma 

 hairs, practically a complete stigma. In 

 Fig. 7 the transformation is very in- 

 complete and the hairs formed suggest 

 the toothing of the awn. It has been 

 previously noted in barley that the awn 

 is physiologically correlated to the 

 stigma. In the modified stamen the 

 filament invariably unites with the af- 

 fected part and forms practically one 

 body. 



That the explanation given for Phyl- 

 lody cannot be completely applied in 

 this case is obvious, because genetically 

 the stigma hairs belong to the carpels, 

 and are very closely related to the em- 

 bry(T forming leaf structure. 



That an organ-forming substance of 

 a different organ may have influenced 

 the Anlage of the sporophyll is possible, 

 as suggested by Sachs and Loele. 

 ( Sachs Ueber Wachstums periode und 

 r.ildungsreize. Flora, 1893, p. 217. 

 See also I. Loele. Bot. Gazette, 1915, 

 \'ol. GO, p. 249; \'ol. 02. p. 293; 1917, 

 \'ol. 63, p. 25.) Goebel {loc. cit.) 

 considers hormones and changes t)f the 

 concentration of the protoplasmic lluids 

 as possible explanations. 



The fact tliat this anc^naly has been 

 found in the greenhouse suggests that 

 abnormal physical factors of tempera- 

 ture or moisture may have a bearing on 

 this phenomenon. 



166 



