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THE AMERICAN NATURALIST [Vol. XL 



work on Zamia (: 01) had appeared somewhat sooner the descrip- 

 tions as to Ginkgo would necessarily have been different in the 

 above-mentioned work. Webber shows very conclusively that 

 in Zamia, and in all probability in Ginkgo also, the division into 

 stalk and central cell (body cell) does not leave those cells side by 

 side, but in the position found in the other groups of gymnosperms. 

 The bulging of the last vegetative prothallial cell into the stalk 

 cell probably led to a wrong interpretation of the earlier obser- 

 vations. Webber pointed out that the work of Ikeno and Hirase 

 was obscure on this point, and that before it can be certainly con- 

 cluded that any Cycad divides so as to bring the stalk and body 

 cell side by side, except as an unusual variation, the figures show- 

 ing the stages of development must be more convincing than those 

 now available. 



Lawson ( : 04) found a variation in the behavior of the nuclei 

 and cells in the pollen grain of Cryptomeria japonica, as compared 

 with other gymnosperms which have the same number of nuclei. 

 The primary spermatogenous nucleus is free in the cytoplasm of 

 the pollen grain and not separated from the tube nucleus by any 

 membrane, except for a short time, and even then the membrane 

 is so difficult to distinguish that it almost escaped the observation 

 of the author. 



A'ariations in the pollen grain of several gymnosperms have been 

 reported in the Botanical Gazette by Coker ( : 04a) one of which is 

 much like some of those found in Picea excelsa by the present 

 writer. Coker's Figure 7 of Larix europcea is similar to my Fig- 

 ure S. His Figure G is merely an earlier stage of the same thing. 

 His Figure S of Larix europwa and Figure 4 of Cupressus semper- 

 vireus sliow a condition that is like that found by Lawson in 

 Crypfomrria ja pnn irti . Cokor's Figure 9 of Larix europa^a shows 

 the la>t division wall in the i)()llen grain straight across, as is usual 

 in (;vcas, instead of the strongly l)ulging wall that is usual in Larix. 



C'oker merely reports these as abnormal grains, aj)parently not 

 attaching any significance to them. It sccins to the writer that 



