The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . t strengthbefore winter. My fasciated races of Crepis biennis andTaraxacum officinale are very instructive in this connec-tion. Sowings of Crepis, made in April and May, gavefrom 30-40% of fasciated individuals. Sowings madeat the end of Ji-ily produced 20% only, and those made inSeptember none at all. Similarly, Taraxacum officiiiale,when sown in spring, produced 13 to 27% of a sowing made in August did not produce evenso much as a single flattened flower-stalk. \^ur la cii
The mutation theory; experiments and observations on the origin of species in the vegetable kingdom . t strengthbefore winter. My fasciated races of Crepis biennis andTaraxacum officinale are very instructive in this connec-tion. Sowings of Crepis, made in April and May, gavefrom 30-40% of fasciated individuals. Sowings madeat the end of Ji-ily produced 20% only, and those made inSeptember none at all. Similarly, Taraxacum officiiiale,when sown in spring, produced 13 to 27% of a sowing made in August did not produce evenso much as a single flattened flower-stalk. \^ur la ciillurc dcs monstruositcs, Compt. rend., Paris, Jan. 1899;Sur la culture dcs fasciations dcs espcccs aiinucllcs ct bisa)i)ii(cllcs,Revue gen. d. Bot., 1899, Vol. XI, p. 136; and Ucbcr die Ahhdni^ig-kcit dcr Fasciation vom Alter bei czieijdhrigcii PHanzen, BotaniscliesCcntralblatt, 1899, Vol. LXXVII. 500 The Inconstancy of Fasciafcd Races. In races of this kind all conditions of the environ-ment are of importance. By crowding, the proportionof fasciated individuals can be reduced, for instance, from. Fig. III. Agrostemma plant the main axis of whichhad been cut off at o. The cotyl-edons have dropped off at C andC. Their axial twigs are fasciated,and instead of producing decussateleaves, bear multiple whorls. Theysplit occasionally at the nodes,forming forks with branches at(/, b, c, d, e and /. Just above f thecalyx of the flower is spiral (kk),and fused with the uppermost fo-liage leaf (b), by which the flowerstalk is seen to be twisted. (1892.) 40 to 5%. Even if the number of fasciations is calcu-lated per area of the bed, a small number of specimensgive a prospect of obtaining more- fasciations than a Tlie Inheritance of Fasciations. 501 larger number planted on the same area, but too close to-gether. The number of fasciations can be diminishedby cultivation on sterile sand and increased by the addi-tion of manure. The most numerous and the finest in-stances of the an
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