Suaw: Note ON THE PAPAVERACEAE 433 
In Chelidonium, however, a more considerable difference exists. 
Both primine and secundine persist and take part in the formation 
of the seed-coat. In fact the outer cell-layer of the secundine is 
rather the most indurated of the four or five cell-layers which give 
protection to the endosperm. 
SUMMARY 
In Sanguinaria the microspore mother-cells are formed during 
the season preceding blooming, but their division and the forma- 
tion of the ovular integuments and of the embryo-sac occur after 
renewal of growth in the spring, just before blooming. 
In Sanguinaria, Chelidonium and Eschscholtzia an open canal 
extends from the carpellary cavity to the exterior. 
In the above-mentioned forms the antipodal cells are very 
prominent, especially so in Eschscholtzia, and the adjacent nucel- 
lar cells are thick-walled and rich in contents. 
In Sanguinaria and Eschscholtzia the secundine eventually dis- 
appears and the inner cell- layer of the primine constitutes the most 
important element of the testa. In Chelidonium both primine and 
secundine persist and take part in the formation of the seed-coat. 
Explanation of plate 15 
ll drawings were made with camera lucida. Figures 3, 4, 5 and 6 are drawn to 
the same scale. 
Fic. 1. Embryo-sac of Aschscholtzia. 
Fic. 2. Embryo-sac of Chelido nium 
Fic. 3. Section through the sertegernicenth of Sanguinaria, immediately after their 
formation ; a, secundine, 4, primine. 
IG. 4. The same at the time of completion of egg-apparatus. The middle layer 
of the primine has undergone division 
IG. The same at the time ‘hes endosperm cells are being cut out. The secun- 
dine is breaking dow 
Fic. 6. The same at maturity of seed, showing the inner layer of the primine 
greatly enlarged and indurated and containing crystals of calcium oxalate. 
