Ill 



male flower, showing presence of 

 perianth (P.)- X 300. 



Fig. 16. Thick longitudinal section of 

 older female flower, showing crenate 

 free border of the integument. X 50- 

 Letters as in fig. 13. 



Fig. 17. Surface view of young female 

 flower after cutting away of the ex- 

 ternal Perianth , showing fiogershaped 

 processes on the free border of the 

 integument X 50. 



P. 0. 1. 0. E. P. =: Place of Insertion 

 of External Perianth. 



Fig. 18. Longitudinal section of adult 

 female flower. X 50. 



E. P. :=z fleshy External Perianth. 



L P. =: stoney Internal Perianth. 

 I. =r integumental Stigma. 

 N. r^nucellus, showing at the 

 top the begin of the formation of the 

 pollenchamber. 



Fig. 19. Longitudinal section of the nucel- 

 lus, showing stretching of hypodermal 

 cells after Strasburger. 



Fig. 20. Idem, showing formation of 

 embryosac mothercells, after Stras- 

 burger. The dark black contour of 

 the embryosac mothercells has been 

 put in by me. 



Fig. 21. Idem, after Strasburger. Three 

 embryosac mothercells are present, 

 Darkblack contour put in by me. 



PLATE IV. 



Fig. 22. After Strasburger. As fig. 21 PI. 

 III. Tapetal cells very plainly visible. 



Fig. 23. As fig. 22. The first nuclear 

 division takes place in the central 

 embryosac mothercell. 



Fig. 24. After Strasburger. Formation 

 of embryosacs by the embryosac 

 mothercells. The two sistercells to 

 the right both develop to embryosacs, 

 of the left embryoaac-mothercell only 

 the upper daughtercell develops. The 

 lower one degenerates. The red color 

 put in by me; here and in the next 

 figure the embryosac which afterwards 

 . is destroyed is indicated by dotted 

 lines. 



Fig. 25. After Strasburger. The cells 



with the red contours are the daugh- 

 tercells of an embryosacmothercell, 

 the upper one obliterates, the lower 

 one becomes an embryosac. 



Fig. 26. Longitudinal section of adult 

 flower, showing position of young 

 embryosacs. X 50. 



Fig. 27. Cluster of embryosacs from fig. 

 26. X 850. 



Fig. 28. Embryosac showing the nume- 

 rous free nuclei and the constriction 

 below the middle. X "5. 



Fig. 29. Formation of prothallium in 

 lower part of embryosac. X '75. The 

 prothalliumcells are as yet polynu- 

 cleated. An embryosac being pushed 

 aside is seen near the top at the right 



PLATE V. 



Fig. 30. Three embryosacs lying in one 

 row. X 100. 



Fig. 31. Two embryosacs, the one to 

 the right will survive, the other one 

 obliterate. X 100. 



Fig. 32. Three embryosacs, after dissol- 

 ving of the contents by means of 

 chloral hydrate. X 50. The two re- 

 duced ones are lying at the top of 

 the adult one, symmetrically in 

 regard to the median line. The large 



embryosac has not yet developped a 

 prothallium. 

 Fig. 33. After dissolving of the contents 

 by means of chloral hydrate. The 

 contour of the large embryosac is 

 red, it has formed its prothallium 

 in the basal part. The two reduced 

 embryosacs , red also, are lying about 

 symmetrically to the left and right 

 of the median line, between them 

 the pollentube (drawn blue) has pas- 



