2 8o 



SCIENCE PROGRESS 



tubes to the assimilatory tissues. He stated that the tubelets 

 "... often lie with their occasionally branched ends on palisade 

 cells arranged as in a sheaf," and that "... when such a direct 

 connection is not possible, funnel-shaped collecting cells 

 negotiate the transference of the products of assimilation to the 

 efferent laticiferous tubes" (figs. 15, 16). Schimper, however, 

 made some criticisms upon this point in 1885, though his work 



Fig. 14. — Laticiferous tube and portion of epidermis from Hypocluvris radicata. 



Fig. 15. — From leaf of Euphorbia iiiyrsinites showing relation of laticiferous tubes 



to assimilatory cells. 

 A, palisade ; B, collecting cell ; C, laticiferous tube. 



Fig. 16. — From leaf of Euphorbia biglandulosa. 



Lettering as in Fig. 15, 



(Figs. 14-16 after Haberlandt.) 



upon laticiferous tubes appears to be entirely ignored in 

 Haberlandt's treatment of the subject in his PJlanzcnanatomie of 

 1904. Schimper failed to find such anatomical relations as 

 Haberlandt described and wrote that the " statement that the 

 laticiferous tubes branch under the palisade cells and that their 

 ends are pressed to them, in order as it were to receive 

 assimilates, is founded on an entirely isolated and exceptional 



