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POPULAR SCIEXCE MOXTHLY 



these structures to the action of chemical agents, not ordinarily en- 

 countered by the elements in question, at a time before fertilization 

 occurred. The tests were planned to include the use of a solution of 

 high osmotic value, and mineral compounds, some of which are toxic 

 in concentrated solutions and stimulating in the proportions used. 

 The probability of success would be heightened with the number of 

 ovules contained in any ovary operated upon, and therefore the common 



evening-primrose, Oenothera biennis, 

 Bairn an nia odorata a relative of it 

 and a member of the same family, 

 Begonia, Cleome, Abutilon, Splue- 

 ralcea and Mentzelia and others 

 were experimented upon. Without 

 recourse to the detail of the work, 

 it may be stated that the use of 

 radium preparations, sugar solutions 

 (10 per cent.), and solutions of 

 calcium nitrate one part in one to 

 two thousand of distilled water with 

 capsules of Baiinannia odorata, and 

 zinc sulphate in a stronger solution 

 used with CEnotltera biennis, was 

 followed by very striking results. 

 In the first-named plant, there ap- 

 peared in the progeny obtained from 

 a few capsules of one individual, sev- 

 eral individuals which were seen to 

 differ notably from the type with the 

 appearance of the cotyledons, and, 

 as development proceeded, it was 

 evident that a mutant had appeared 

 following the injections and nowhere else, and thus to have some direct 

 relation to the operation. The characters of the newly arisen form 

 were so strikingly aberrant as to need no skill in their detection. The 

 parent was villous-hairy, the mutant entirely and absolutely glabrous, 

 the leaves of the parent have an excessive linear growth of the marginal 

 portions of the leaf-blades and hence become fluted; the excess of 

 growth in the mutant lies along the midrib and the margins become 

 revolute. The leaves are widely different in width, tbose of the mutant 

 being much narrower. The parental type is of a marked biennial habit 

 and near the close of the season the internodes formed are extremely 

 short, which has the result of forming a dense rosette; the mutant 

 forms no rosette by reason of the fact that the stem does not cease, or 

 diminish its rate of elongation, and hence presents an elongated leafy 

 stem, which continues to enlarge as if perennial. The first generation 



FlG. 8. MUTANT OF THE COMMON EVEN- 

 ING Primrose, induced by Treatment 

 of Ovules with Solutions of Zinc Sul- 

 phate. 



