Jan., 1903.] 



Claytonia virginica. 



353 



Ohio Naturai^ist. 



Pla/c ja. 



Cook on "Claytonia virginica." 



EXPLANATION OF FIGURES. 



In the drawings, Leitz stand and a 15. and I,, camera lucida were used, l-'igs. i to S. a 

 Zeiss ocular and a 1-12 B. and L immersion; in Figs. 9 to 21, a No. 6 Zei'^s ocular and 

 Zeiss objective; in P'ig. 22, a No. 4 Leitz ocular and a No. 5 Leitz objective. 



Archesporial cell and two tapetal cells. 

 ■2(1. One tapetal cell and beginning of the second division in the formation of the 



megaspores. 

 Four megaspores and three tapetal cells. 

 Functional me,gaspore. 

 Two-celled sac 



Four-celled sac and tapetal cells. 

 Eight-celled sac. showing conjugation of polar nuclei. Also the three antipodal 



cells just before disorganization. 

 Polar nuclei approaching. 

 Eight-celled .=ac after conjugation of polar nuclei. First stage in absorption of 



nucellus from antipodal end of sac. 

 Two-celled embryo and persistent synergid. 

 Four-celled embryo and persistent synergid. 

 Six-celled embryo. 



F'ight-celled embryo and peristent synergid. 

 Enibrvo " " " 



8. 



o. 

 10. 

 II. 

 12. 



!4. 



I.S. 

 16. 



17 

 iS. 



19- 



21. 



22. 



'• with longitudinal wall in first suspensor cell, 



and persistent synergid. .\lso endosperm. 

 .\ntipodalendof sac. showing massingofendosiierm labont .sameageas 

 Spherical embryo and persistent synergid : c, cotyledon ; p. i>lumule. 

 l-;mbryo showing suspensor ; c, cotyledons (one largeand one small i; p 



atid formation of calvptrogen a) above suspensor. 

 liase of large embryo .showing plumule (p , rudimentary cotyledon ici 



ca p ( r I . 

 Part of embrvo showing rudimentary cotvledon (c1 and plumule (p). 

 Entire ovule' showing mature embrvo, with large cotyledon curved around a 



central mass of nucellus cells, which are rich in starch; a, outer integument; 



b, inner integument; end., endosperm. 



in I-'ig.i6). 

 , iihnniile: 

 , and root- 



