( 498 ) 



moni (){' llio leaves, jtarliv in ('(iiuKM'lioii \\\l\\ tlio s|»liliiim' up ofilie 

 ('Oiili';il-('\ liiidci- in llioso organs of inaiiv plants, ('oiicerning' tlie 

 lallei' |)öinl van Tik(;hk.m iiinisclf and of lalc a numlx'i' of Aniericnii 

 and Enulisli invpslii>atoi's: (tWYNNK-A aicuivn. .Ikitkf.v, Iioodt.k, Failt,, 



WORSDKI,!.. ])l{KT:ANr) FaKMKK (!C' HiT.L. Miss KaIU). TaNST.KV ^' LlLllAM, 



1)|{KHM',|{ lia\(' slicd mucli liiilil. In all lliose (•as(>s in wliicli slems 

 show a number of loose slrinu's, reuai'dcd liv some as pai'ts of a 

 ceiilral-cylindei- (scliizoslely), Ity o(liei-s as vascular bundles, a siiiiilo 

 een(ral-e\ linder. the monoslelic siruclure. is rule in the youngest 

 intcrnodes of the plant, in hypo- and cpieoiyl and in the internodes 

 follow ing immediately. 



l)Ut in most cases there is no (piestion ahoid scliizoslely and so 

 according to van Tikoiikm wc must expect moiutstely. iiowex'er it is 

 a fact, that \\'hilst in cxci-y root the most siipcrliciai microscopic 

 investigation easily proxcs the existence of a centi*al-cylinder, this is 

 not at all the case foi- juany stems. 'IMie inner layer of the cortex 

 ( eiidodermis ) . it is ti-iie. is often developecl as a hundle-slieath 

 ijidicating as that of the loot does, the houndai-y of the central- 

 cylinder, or al^o it contains starch-grains, so that a dislijict stai'ch- 

 slieath is fornu'd : hut in a great many other cases, also in an inx'cs- 

 tigation made for that purpose, as was doiu' ity II. Fiscmkr, it has 

 not been possible to point out a well defined central-cylinder. I^'isciiku 

 toiind in 100 in\ cstigatetl plants oidy in o2 cases a distinct eiidodermis. 



It has now been sjiow n by .Air. Schoitk that liiis objection to the 

 Stelar-lluMtry does not exist in reality. He collected out of tiie lite- 

 rature on this subject numbers of cases, in which a distinct endodermis 

 had ix'eii obser\'ed in some sha|»e or other, lie himself studie<l a 

 great number of steins of dilferent plants and then it was exidenl 

 ho\x necessary it is to examine these organs in dilferent and especially 

 in young stages of their development, a thini'' Fisciikr had not done. The 

 result of this method of working was. that of about 400 dicotyledonous 

 ]ilants only in 7 no distinct endodermis was come across and among 

 these 7 there were yel 4 which even showed a sharp boundary of 

 the central-cylinder. Also the greater pari of the Monocotyledonous 

 |)laiits |)ossess an endodermis. It is not to be found in (iymnos[)erms 

 but yet liere as is the case in most of the abo\e-inentioned exceptions, 

 a <listinct boundary between cortex and central-cylinder is ofteji to 

 be seen. So this i-esnlt is very favonrable for the Stelar-theory and 

 is a contribution to its scientilic conlirmation. 



r>iit in yet another manner has Mr. Schoitk endeaxoured to lest 

 the Stelar-theory, a test, Avhich it is true has led It» a negative result, 

 but which enables us to draw weightv conclusions Avith regard to 



