. Botany all the year round; a practical text-book for schools. Botany. 204 THE FLOWER. 391. â Cross section of ovary of iris flower: c, c, car- pels; /, /, celis^ or loculi; ov, ovules; pi, placenta. parietal (Sees. 103, 109). Draw a cross section of the ovary; how many cells has Examine with a lens the little flap under the two-cleft apex of one of the stigmas, and look for a moist spot to which the pollen will adhere. Label this in your longitudinal sketch, stigmatic surface. No seeds can be matured unless some of the pollen reaches this surface ; can you think by what agency it is car
. Botany all the year round; a practical text-book for schools. Botany. 204 THE FLOWER. 391. â Cross section of ovary of iris flower: c, c, car- pels; /, /, celis^ or loculi; ov, ovules; pi, placenta. parietal (Sees. 103, 109). Draw a cross section of the ovary; how many cells has Examine with a lens the little flap under the two-cleft apex of one of the stigmas, and look for a moist spot to which the pollen will adhere. Label this in your longitudinal sketch, stigmatic surface. No seeds can be matured unless some of the pollen reaches this surface ; can you think by what agency it is carried there .â ' What insects have you seen hovering about the iris .'' Notice that in draw- ing his head out of the flower, an insect would not touch the stig- matic surface, since it is on the upper side of the flap and he would be probing under it. But in entering the next flower that he visits, he is likely to strike his head against the flap and turn it under, thus dusting it with pollen brought from another flower. Sketch a sepal and a petal separately, and note their differences as to shape, color, and texture. Hold each up to the light and observe the veining. If this is not clear, stand a specimen in red ink for two or three hours and examine it again. Is it parallel or net veined 1 Can you think of a use for the crest of hairlike filaments on the upper side of the sepals ? Examine a bud in cross section. Notice how the sepals and petals overlap, and draw a diagram of the section. This manner of arrangement, where the outer edge of one piece covers the inner edge of the one next above it (Fig. 387), is said to be convolute. Draw diagrams showing the horizontal and vertical arrangement of parts in the iris. What is its numerical plan.' Is it symmetrical > Regular.' Are the parts all free ? If not, which are united among themselves or with other sets of organs .â â above or below the other parts .'. Please note that these images are extracted from scanned page imag
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