抄録
1. The chromosome numbers of the following genera have been determined for the first time:-
n 2n
(1) Angelonia grandiflora C. Morr. 10 20
(2) Angelonia cubensis var. alba 10 -
(3) Russelia juncea Zucc. 10 -
(4) Russelia rotundifolia Cav. 10 -
(5) Stemodia viscosa Roxb. 21 -
(6) Dopatrium lobelioides Benth. 7 -
(7) Scoparia dulcis Linn. 20 -
(8) Vandellia crustacea Benth. 21 -
2. Details of meiosis have been worked in Angelonia grandiflora. Secondary association has been recorded.
3. The scope and limitations of secondary association as indicating the basic number of a genus or of a family are discussed in the light of the observations made in Angelonia.
4. The question of the basic number of the family as revealed by the investigations of previous workers is discussed in the light of the phenomenon of secondary pairing observed in the Scrophulariaceae for the first time in the present investigations, and the conclusion is reached that five is likely to be the primary basic number, and all other numbers represent different balances of this primary number.
5. The origin of the anther sac and the tapetum is described. It becomes bi-nucleate early and remains so until its final disintegration.
6. The pollen grains of Angelonia and Steniodia are bi-nucleate at the time of shedding.
