148 



J. Kki.ixvaax 



Dor.) r.i:.'- v. T-kkivvkx 



III. Anatomy and development of the gall. 



MoLLiAKD, ill his iil)()ve iiieiitioiied article, also gives an aecoiiiit 

 of the anatoiiiy of the gall and its (le\'eloi>iiieiit. For the greater ])art 

 we came to the same results, Imt as we have some more ]>oiiits to 

 relate, we ] »refer to give a review of the facts. 



As is said in the former chapter, the was]» lays its eggs in the 

 young buds of P a ]>. d u b i ii m. With its ovipositor it bores through 

 calyx, corolla and the wall of the pistils and often we found in the 

 latter the channel through which the eggs h ad i)assed. The eggs are 

 placed bet.Aveen the placenta, which are (;overed with ovulae, and in 

 the room, which the septa leave in the middle. 



The ovulae by this time are by no means ready. The integu- 

 ments are only just growing out at the base and the beginning of 

 the formation of the embryosack is to be seen in one large cell in 



the top of the nucellus-tissue. 



The presence of the eggs has 



no influence at all on the growth 

 of the seeds. (Fig. 2), They go on 

 developing till they have obtained 

 the normal structure , showing a 

 very narrow microiiyle and a big 

 egg-cell with syiiergides in the top 

 and three large antipode-cells at 

 the bottom of the spacious em- 

 bryosack. By this time the larvae 

 are hatched and lie between the 

 ovulae , but have at lirst no in- 

 fluence either. 



After some time however we see 

 that the nuclei of all the cells ly- 

 ing nearest the larvae, }^üt bigger 

 and stain deeply (1). Then the pro- 

 toplasma in the cells augments 

 and soon divisions take place. The 



Fig-. 2. — Lougitudiual sectiou of an ovu- 

 le , in the time the larvae are just 

 liatelied. x 500. ' 



(1) For tliiK jmrpose we used material fixated with Kaiser« HgCU-solutions with 

 10 °/o fonmiliue (40 "/o). The ohjects were imbedded in ])aratiue and cut with the 

 microtome in sections oi' 5-10 |-L. As a staining solution we used haematoxyline of 

 Hansen, (after 8töhr) and of Ehrlich. 



