Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . ther and muchmore convincing theory propounded by Weismann, thegreat German careful studies, inwhich the modern meth-ods of microscopic re-search were employed,Professor Weismannfound that instead ofthe organs of the adultbutterfly being presentin the caterpillar, theyreally result from thebreaking down of the va-rious tissues of the larva,followed by a remarkableprocess of rebuilding, inwhich the starting-pointsare certain germinal budsor imaginal disks. This theory has entirely replaced
Nature biographies; the lives of some every-day butterflies; moths; grasshoppers and flies . ther and muchmore convincing theory propounded by Weismann, thegreat German careful studies, inwhich the modern meth-ods of microscopic re-search were employed,Professor Weismannfound that instead ofthe organs of the adultbutterfly being presentin the caterpillar, theyreally result from thebreaking down of the va-rious tissues of the larva,followed by a remarkableprocess of rebuilding, inwhich the starting-pointsare certain germinal budsor imaginal disks. This theory has entirely replaced the incasement theory in theminds of naturalists. The ger-minal buds appear very early inthe life of the insect, sometimeseven before it hatches from theegg. They remain with littlechange throughout the growth ofthe caterpillar. Just before theperiod of pupation, the variousorgans of the larva are brokendown by the action of the bloodcorpuscles, the result of their destruction being a creamymass which is immediately utilized for the rebuilding of 9 Fig. 13. — Side View, a little Fig. 14. — The Empty Chrysalis. Nature Biographies. the tissues. During the process of destruction of thelarval organs the germinal buds remain intact, and simul-taneously they begin to grow by building themselves upfrom the cream)^ material surrounding them. In thisway the buds develop in a short time into the variousorgans of the butterfly. 10
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1901
