IO4 MARGARET C. FERGUSON 



Arnold! ('oo) found that substantially the same thing was true 

 in Cephalotaxus. He was not able to detect the passage of the 

 nucleoli from the sheath-cells into the egg, but, since these 

 granules were present on both sides of the membrane of the 

 egg-cell he accepted the fact of their transference. I have 

 frequently seen a nucleolus partly without and partly within the 

 nucleus of a sheath-cell ; but in no instance could I be sure that 

 such a condition was not the result of mechanical displacement. 

 Ikeno ('98) found direct evidence that the nutritive spheres in 

 Cycas are of nuclear origin. But no such phenomena as he 

 observed in Cycas occur in Pinus. Platner ('86) described the 

 passage of the follicle-cells into the ovum in Helix, and a few 

 other such instances have been recorded in animals. Arnoldi 

 ('oo) has recently noted a most remarkable migration of whole 

 nuclei from the sheath-cells into the egg in several species of 

 pines. He has observed, in a single series, as many as one 

 hundred and fifty nuclei passing into the ovum. From the fact 

 that Arnoldi writes " Strobus" in a parenthesis after Pinus 

 Peuce, I infer that he employs the terms as synonyms ; but I 

 find no authority for such a usage, and cannot accept his con- 

 clusions as holding good for -Pinus Strobus. It does not seem 

 possible that, in a careful examination of several thousand 

 archegonia, so obvious a phenomenon as that described by 

 Arnoldi could have % escaped detection; and I must, therefore, 

 conclude that it does not take place in the species of pines 

 which I have studied. I fully believe that the sheath-cells play 

 an important role in the nutrition of the egg ; but it is the 

 method by which this is accomplished, as described by Arnoldi, 

 that I cannot accept for the species of pines studied. Coulter 

 and Chamberlain ('01) not only accept Arnoldi's observations 

 for Pinus but describe a like phenomenon in Cycas. Basing 

 their statement on the results of Ikeno's studies, they record, on 

 page 22, the following surprising fact with reference to Cycas: 

 "The contents of the jacket-cells, nuclei and all, now pass 

 through the pores into the central cell." I find no authority 

 for such a statement in Ikeno's paper. If I correctly translate 

 the German, Ikeno describes neither the transmission of the 

 nucleus nor of the cytoplasm from the sheath-cells into the egg, 



