Manchester Memoirs, Vol. Ivii. (19 13), No. 11. 15 



the protoplasm and grows towards the nucleus i^Pl. II., 

 Fig. 22), which often becomes displaced to the centre 

 of the cell, appearing then to be slung by delicate 

 protoplasmic strands to the peripheral cytoplasm. The 

 haustorium enters into contact with the nucleus. Fine 

 haustoria may also be seen to have entered and to be 

 growing along the protoplasmic strands toward the nucleus 

 {Pi. /., Fig. 7), {PI. 11, fjg. 17). There is at no time any 

 appearance of an in-growing sheath or cap of cellulose as 

 has been described for the haustoria of some other fungi." 

 With the advance of the haustoria towards the nucleus 

 the chloroplasts become grouped round the latter {PI. II, 

 Fig. 17). They gradually lose their contour, become 

 paler in colour and more highly refractive, and finally 

 lose their identity. The protoplasm near the nucleus 

 then appears denser, and of a greenish colour on account 

 of these disintegrated chloroplasts {P/. I., Fig. 7). 

 Ursprung,^" in discussing the microscopic signs of death 

 in cells, regards the wandering of the chloroplasts to the 

 middle of the cell, the rounding of their contour and the 

 loss of their typical structure and colour, as among the 

 earliest signs of death. In optical section these cells, 

 when studied fresh, have all the appearance of living cells, 

 being quite turgid and having the cytoplasm and nucleus, 

 which are more easily seen than in the uninvaded cells, 

 occupying the cell as already described {PI. II., Fig. 17). 

 A series of plasmolysis experiments was tried. Thick 

 hand sections through the living petiole bearing a pustule 

 were mounted in water and rapidly observed, the atten- 

 tion being fixed on one or two of the invaded cells. 

 These were rapidly drawn with the aid of the camera 



'-' Guttenberg, " Beitrage z. physiol. Anat. der Pilzgallen," 1905, pp. S 

 and 42. 



^^"Lebender Zellen urn Saftsleigen.'" Bcihefle z. Bot. Ccntralb., 

 Ed. XXVIII., H. 2. 



