96 



THE BOTANICAL MAGAZINE. 



[Vol. XXXYI. No. 428, 



Sterile gametes and zygotes, variation in seedlings 



Considerable irregularities in meiotic divisions will naturally cause 

 inadequate distribution of idic(3) substances, and will result in the 

 sterility of the polleu grains and embryosacs and of the seeds. To 

 obtain certain numerical relations in this respect the writer counted 

 the number of the grains in anthers and seeds in capsules as in the 

 following table. The counting was made in each anther and cap- 

 sule, but the total number only is given here : 



Fertile and sterile pollen 



Fertile grains. 



Sterile grains. 



grains in 5 anthers. 







11757 



5 644 (48.00^) 



6 113 (52.00 %) 



Seeds, seed-like structures 



Seeds and 



Abortive ovules. 



and abortive ovules in 



seed-like structures. 



(Sterile and some un- 



115 capsules. 



(ovules received sound pol- 

 len grains and those 

 received unsound 

 pollen grains) 



fertilized embryosacs) 



42971 



2 17 2 3- (50.55^) 



212 4 8 (49.45 %) 



From this data we see that the abortive spores amount to ca. 

 50 per cent., which agrees with the percentage of abnormal mitosis 

 in the pollen formation given before. The germination test was also 

 made with each of the seventeen capsules, the result of which is as 

 follows : 



Total number of seeds and 



Seeds germinated. 



Seeds not-germinated. 



seed-like structures in 



(normal seeds) 



(seed-like structures) 



17 capsules. 







3660 



12 91 (35.27 ^) 



23 6 9 (64.73^) 



The variations in the form, size, number and colour of cotyle- 

 dones were observed in the seedlings. Among them a few O. mut. 

 albida- and oblonga-like plantlets appeared. In one case one hundred 

 and seven out of one hundred and nine seedlings raised from the all 

 healthy seeds of one and the same capsule were transplanted in 

 the pots. When they grew to the two or three rosette leaves stage, 

 seven O. mut. nanella-like plantlets appeared, one of which was 



