. A textbook of botany for colleges and universities ... Botany. REPRODUCTION AND DISPERSAL 86i. length that the insects are unable to lay their eggs in the right spot (fig. 1188). But in the staminate figs, known as caprifigs, there are short-styled rudiments of pistillate flowers (often called gall flowers, fig. 1189), in which eggs may be placed properly, later hatching into wasps. Some stimulus exerted by the insect causes the ovary primordia to develop into seedless galls. After a time the males hatch, eating their way out of the galls in which they developed and into the galls occu- pied
. A textbook of botany for colleges and universities ... Botany. REPRODUCTION AND DISPERSAL 86i. length that the insects are unable to lay their eggs in the right spot (fig. 1188). But in the staminate figs, known as caprifigs, there are short-styled rudiments of pistillate flowers (often called gall flowers, fig. 1189), in which eggs may be placed properly, later hatching into wasps. Some stimulus exerted by the insect causes the ovary primordia to develop into seedless galls. After a time the males hatch, eating their way out of the galls in which they developed and into the galls occu- pied by developing females; copulation is followed by the death of the males within the caprifig. The fe- males thereupon escape (fig. 1190), crawling over the staminate flowers of the caprifig and be- coming dusted with pollen; those that chance to visit figs incidentally pollinate the stigmas therein, but have no progeny, while those that go to caprifigs have prog- eny, but are of no service in pollination. One of the strangest features of a process strange throughout is that the pistil- late flowers mature two months before the staminate flowers; however, by the time the latter are mature, another crop of synconia has developed with stigmas ready for pollination, so that stigmas of a given generation are pollinated from inflorescences of the preceding generation. In southern Italy there are three such crops of figs and caprifigs each year (viz., in April, June, and August), and three corresponding generations of wasps. This symbiosis between Picus and Blastophaga has been denominated mutualism, but surely it is a somewhat destructive form of mutualism, where death without progeny comes to such a large proportion of the symbionts on each side, namely, to the female insects that enter the figs and to the pistillate flowers of the caprifigs. Centuries before the process of pollination was discovered, the ancients cultivated the commercially valueless caprifigs, and placed branches
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
