Anatomie. — Morphologie etc. 277 



another reason for referring that genus to the conifers rather than 

 to the cycads. Jongmans. 



Blodgett, F. H., Morphology of the Lemna frond. (The Bot. 

 Gazette. LX. p. 383-390. PI. 14. 1 Fig. 1915.) 



In this paper an effort is made to show what structural units 

 contribute to the formation of the frond of Lemna, and the part 

 taken by each in the development of the successive vegetative 

 individuals. 



The Lemna frond is a propagative structure consisting of a 

 terminal leaf; a bud inclosed by a flattened bud scale, the base of 

 which is fused to the base of the leaf and laterally to the stem; 

 and an apical region from M^hich new fronds are developed. Two 

 buds are formed through the Splitting of a Single bud rudiment by 

 vertical pressure during early stages of grov^^th. The frond meets 

 the conditions of a floating habitat in which the tension of the sur- 

 face film apparently is an active factor. Through the lack of space 

 for vertical succession, the several outgrowths from the apical re- 

 gion are liberated as a horizontal series, the overlapping of succes- 

 sive individuals forming an element of confusion in an examination 

 of their structure. Jongmans. 



Buplingame , L. L., The Morphology of Araucaria brasüiensis. 

 III. Fertilization, the embryo, and the seed. (Bot. Gaz. 

 LIX. p. 1—39. PI. I— III. 1915.) 



This paper is divided into two parts. The first part contains 

 the author's own observations on the fertilization, the proembryo, 

 the embryo, the endosperm and seed of Araucaria brasüiensis. 

 These researches are summarized as follows : 



Pollination occurs on the scale at a distance from the nucellus. 

 The pollen tube is very long and gives rise to many small lateral 

 haustorial branches. It combines features of conifers and cycads to 

 a certain extent. This is probably an extremely primitive form 

 of tube. 



The body cell divides in the extra-nucellar part of the tube a 

 month or more before fertilization. The central cell of the archego- 

 nium divides very late or perhaps not at all, except in cases of 

 delayed fertilization. 



The male cells are very large and unusually active, as well as 

 long-lived. Blepharoplast-like bodies are found in the male cyto- 

 plasm. The male cell passes through the neck without injuring the 

 neck-ceils. It com.es into violent contact with the egg and frequently 

 displaces it. 



The free nuclear divisions of the proembryo are restricted to 

 the male cytoplasm that surrounds the fusion nucleus, which per- 

 sists and grows with the proembrj^o. The male cytoplasm around 

 the older proembryo may be surrounded by a membrane. 



The number of free nuclei in the em.bryo varies from 32 to 45 

 or perhaps more. When walls form che free nuclei are arranged 

 concentrically. 



The Upper peripheral nuclei form the suspensor, the lov/er ones 

 tbe cap, and the middle girdie elongates to unite cap and suspensor. 

 The central cells of the proembryo alone take part in forming the 

 embryo. In the growth of the embryonic group the cap is thrust 

 aside and a cylinder of meristematic tissae is organized. The 



