222 



"Fjjially the oontent in tannic substance s should be consid- 

 ered, which, as is well known, maKes many galls of practical 

 importance. Those galls are histologically interesting in 

 which the storage of the tannic substance is restricted to def- 

 inite zones, Th^ bark of many Oynipides galls is strikingly 

 rich in this. In them the tissue, resembling star -par enohymD- 

 si-noe it abounds in interstices, is filled with the substances. 

 The antiseptic action of the tannic substance may, under cer- 

 tain circumstances, be of significance in the development of 

 the galls and their occupants. Nevertheless, it is noticeable, 

 that, "tannic substance balls"-*- may be found in the nutritive 

 parenchyma of many CynipiAes larbae, and are devoured by the 

 gall animals, but are, according to Hartwioh, thrown off again 

 as excreta. According to Beverinck (loc. cit) and Hartwich, 

 forms which are at once conspicuous because of their very dark 

 color, occur in the various elliptical galls, in the products" 

 of Oynips Kollarl . C. lignicola . G. insana ("Bassorah galls"), 

 0/ •fcinctoria eioT Also they are knoxm already 'to Laoaze-Duthiere, 

 For th0 tannic substance in other hyperplasip-s, compare p* 16T« 



Finally, the anthocyanin content of many galls should be 

 mentioned. Many g§ills, just like normal fruits, get "red checks" 

 through the act ion" of light ( Neroatus gallarum . HoiTnomylajgfa^i, 

 etc.); a reddish tone is thoroughly characterir-^c of mny 

 ( Oynips terninalis . vefy many Phytoptus sac galls etc.). In 

 many others the anthocyanin content is restricted to definite' 

 parts of the tissue. The red zones, ten or more layers thick, 

 in the galls of Kematus Vallisnerii (on Salix) are very notice- 

 able. On the upper side {the side toward the light) the cell 

 layers derived from the mesophyll become colored unusually hxe^- 

 ly - those derived from the epidermis were colorless in the 

 examples which I investigated. 



The present pages give indeed no exhaustive anatomy of 

 prosoplasmatic gallsj- only the outlines of such an one - cor- 

 (261) resT3onding to the task of our book - may be given here.^ What is 

 given mav w«ll furnish sufficient material for a comparison of 

 the various pathologica]. tissue forms with one another,- whicn 

 we consider the aim of this exposition. Hew points of view for 

 our question would scarcely have been acquired by a cleeper in- 

 vestigation of the galls, which have been studied up to the 

 present. 



In conclusion, we should remember that the number of galls 

 which have heen closely investigated is still very small; we 

 know practically nothing concerning the forms outside of Biirope 

 or in the tropics, least of all concerning their ^^atomy and 

 development. And also a thorough study of the native galls is 

 in many cases still urgently desired, 



■^ Hartwich, lOc. cit. 



