June, 1905.] Embryo Sac and Evibryo of Batrachium. 363 



-Stigma showing germinating pollen grains. 



-Young two celled embryo and endosperm. Possibly the remains 



of the second generative nucleus and pollen tube. 

 -Antipodals with live nuclei. 

 -Four celled embryo and persisting synergid. 



-Single integument, nucellus and embryo, the remains of synergid, 

 endosperm, and three nuclei of the antipodals. 



-More matvire embryo showing dermatogen layer and division in 

 suspensor cells. 



-Endosperm from sac of a four celled embryo showing faint 

 radiations. 



-Endosperm cells showing variation in shape and size, a-average 

 cells ; b-peripheral cells ; c-cells near embryo ; d-in antipodal 

 region. 



-Embryo sac showing the arrangement of endosperm cells and the 

 remains of antipodals. 



-Closely packed endosperm filled with starch. From an embryo 

 sac containing a mature embryo. 



-Embryo showing rather diagonal division of the suspensor. 



-Section of older embryo cut slightly diagonal but showing the 

 beginning of cotyledons. 



-Nearly mature embryo showing cotyledons, dermatogen, 

 calyptrogen, pleurome and traces of the suspensor. 



-Crescent shaped cells of inner wall of carpel and elongated cells 

 at right angles to the first; integument and nucellus. 



-Section of a mature carpel showing these crescent and elongated 

 cells hardened and perforate. 



Leaf Expansion of Trees and Shrubs. No detailed record 

 of the expanison of leaves was kept for the spring of 1905, but it 

 was noted that the beginning of leafing was seven days earlier 

 than in the spring of 190-4. Syringa vulgaris L. came first on 

 March 25, followed by Salix babylonica L., Larix laricina (Du R.) 

 Koch, and L. decidua Mill. Some trees were comparatively 

 earlier than last year and the order of succession was changed in 

 quite a number of species. This was probably due in part to the 

 more uniform advancement of warm weather. Morus rubra L. 

 and Chionanthus virginica L. were the last trees to leaf, coming 

 out on Ma}' 6. 



J. H. S. 



