150 J. Rki.invaax — DocïERS v. Leeuwex 



a seed lias not Ixmmi att:ick<'(l l)y ;i larvae it may ret;iiii more of its 

 original form and at last lies ])ress(Ml between the swollen septa. 



On the outer [)arts of the septa, vvliicli are not used for the for- 

 mation of the larval chambers, a number of seeds ai'e well de\ eloped 

 and can üei'iiiinate in the following' year. 



Thus we see here the remarkable fact , that the animals live 

 free for some time between the sei>ta and the seeds and only at a 

 later ])eriod .yet snrrounded by the ^all-tissue. This inter\al is ra- 

 ther a lon.y one : we saw the e.üiis laid in -lune and in the nnchlle 

 of July the ehanibers in most yalls are only just closed. In the 

 manner in which the tissne de\elo]>s round each lar\a we als(t see 

 a great diflerence co]Ui»ared to the case of the ('yni])idae , where a 

 wall is formed directly round the eggs , which grows on ami then 

 closes to a chand)er. 



When the chand)ers are closed the ]»arenchym which surrounds 

 the larva<^ differejieiates into a nutricious-tissiie. Many layers of cells 

 are formed of which the iniieruiost contain mucli oil in the ]>roto- 

 plasma. Some vows around these inner-layers show a great many grains 

 of am y In m . 



The rest of the parenchym forms a i)rotecting tissne. Tiie cell- 

 walls get lignifted and show many spots. Round each larval chamber 

 a special region is dift'erentiated. The cells there are much smaller 

 and their walls are thicker. At the outer si<le this band gradmilly 

 passes into the lignitied parenchym. For the rest we refer to the 

 article of Mr. Molliard ; all he says farther about the anatomy 

 of the gall we stated in the saiue way. 



We wish to call attention to oiu' im]>ortant fact. The cells which 

 form in the normal case the septa of the papavertVuit , are formed 

 already at the time of infection. They afterwards increase no more 

 by cell-division, but the organs grow by the cells expanding. But in 

 the case of the gall-formafion these cells, which had reatdied the end 

 of their differentiation , are still able to divide by nntosis and to 

 form totally other tissues than they used to. So in the circumference 

 of the larvae the cells are able to form oil and albumen and the 

 adjoining cells form the protecting tissue of thickened ami lignitied 

 cell-walls, which show the well-develo])ed spots. We can only under- 

 stand this if we entertain the o[)inion that in the cells, even in the 

 most developed, there are still other characters , which do not nor- 



