DR. W. R. MCNAB ON WELWITSCHIA. 511 
DESCRIPTION OF PLATE XL. 
The following letters apply to all the figures. 
p. v. punctum vegetationis. 
o. p. outer part of perianth (calyx). 
i. p. inner part of perianth (corolla). 
p. $. primordial staminal cushion. 
$. stamens. 
carpels. 
. Ovular integument. 
a, 
. $. embryo-sac. 
base of female flower (pedicel). 
v. b. fibro-vascular bundles. 
c 
0 
n. nucleus. 
e 
b 
Most of the figures are magnified 70 diameters. All the figures are represented as seen from the front, 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 13. 
except those indicated as being seen from above or in section. 
Male Flower. Figs. 1-10. 
First stage of male flower: outer parts of perianth, o. p.; and punctum vegetationis, p. v. 
x 70 diameters. 
Second stage : outer part of perianth, o. p. ; inner part forming, 7. p.; punctum vegetationis, p. v. 
x 70 diameters. 
Third stage: outer part of perianth, o. p. ; inner part separated, i. p. ; primordial staminal cushion 
indicated, p. s. ; punctum vegetationis, p. v. x 70 diameters. 
Fourth stage: outer part of perianth, o. p., increasing in size; inner part, i. p. (the other is 
posterior and not seen); primordial staminal cushion, p. s.; punctum vegetationis, p. v. 
x 70 diameters. 
Parts of perianth removed. Fifth stage: primordial staminal cushion, p. s.; anterior carpel 
beginning to form, c.; punctum vegetationis, p. v. 
The same further advanced ; flower same distance from growing point as fig. 5. 
Flower next in age to fig. 5. Perianth removed; 6 stamens, s.; carpels, c.; surrounding the 
punctum vegetationis, p. v. 
Same flower, from side, showing the anterior stamens larger than the lateral ones. 
Flower next in age to fig. 7: carpels have completely covered in the punctum vegetationis, a slit- 
like mark remaining; s. stamens; carpels, c. 
Longitudinal section of flower next in age to fig. 9: punctum vegetationis, p. v., very small, 
while the carpels, c, have rapidly developed. 
Female Flower. Figs. 11-19. . 
Earliest stage of female flower: 5. base; punctum vegetationis, p. v. x 70 diameters. 
Second stage: outer lateral lobes of perianth (carpels) beginning to form, o. p.; 5. base; p. v. 
punctum vegetationis. x 70 diameters. 
Third stage: outer parts of perianth (carpels) still further developed, o. p.; cylindrical portion 
above their insertion well developed; punctum vegetationis, p. v., with indications of the 
ovular integument; 5, base. x 70 diameters. 
