

1909] 



BRIEFER ARTICLES 



407 



2. A careful study of the 

 other sections of the series 

 has failed to show any 

 other pollen tube which 



have reached the 



* 1 



• ■ 



might 



archegonium from another 

 direction. 



3. The spindle of the 



EXPLANATION OF 



FIGURES 



All sections 6-8 /* thick; cut 

 with the Cambridge rocking 

 microtome; drawn with camera. 

 In all: n, nucellus; p, prothal- 

 lus; /, pollen tube; a, arche- 

 gonium; v, receptive vacuole; 

 $, oosphere nucleus; <S, func- 

 tional sperm nucleus; 3 2 > 

 secondary sperm nucleus. 



Figs, i and 2. — Stages in 

 the first division of a partheno- 

 genetic proembryo; diagram- 

 matic ; reconstructed from 

 several sections in each case. 



X77. 



Fig. 3.— Spindle of fig. J, 

 showing the comparatively 

 small amount of chromatin 

 substance; drawn from two 

 sections. (No attempt has 

 been made to show all the 

 chromosomes.) X640. 



Fig. 4. — One of the sperm 

 n uclei of fig. 1, showing that 

 these are quite normally organ- 

 ize d. X310. 



Fig. 5. — Diagram showing 

 n °rmal fertilization in one of 

 th e archegonia. X 60. 



Fig. 6. — Sperm nucleus and 

 P^rt of the oosphere nucleus 



X2 5S . 



7— Part of fig. 6. 



of fig. 5 



Xi 



Fig. 

 240. 



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