1889.] BOTANICAL GAZETTE. 245 



protoplasm and the genetic relationship of the associated 

 granules (including, in the widest sense, the nucleus), be 

 made to cast any light on the question of development, as 

 they certainly do upon the kindred question of adaptation ? 

 The answer has been given us very lately by Hugo de Vries 

 of Amsterdam. This investigator, who has done very much 

 to clear up certain obscurities in regard to the external rela- 

 tions of the cell, has recently revised the neglected doctrine 

 of pangenesis and applied it to the question just propounded. 

 De Vries suggests that we divide the hypothesis of pangen- 

 esis as proposed by Darwin into two parts, as follows : (i) 

 In every germ-cell individual characters of the whole organ- 

 ism are represented by material particles which, by their 

 multiplication, transmit to descendants all of such peculiari- 

 ties. (2) All the cells of the organism throw oft', at certain 

 periods of development, such material particles, which flow 

 towards the germ-cells, supplying its deficiencies. Now de 

 Vries asks whether it is not high time for us to look at the 

 first part of this hypothesis again, and abandon the hin- 

 drances which the latter part imposes. If we accept his sug- 

 gestion, and restate the hvpothesis, in view of what has been 

 learned relative to the nucleus and other granules (the troph- 

 oplasts) within the cell, we should then read : 



In every cell at a growing part are all the elements ready 

 for multiplication. Each protoplast possesses the organs 

 necessary for continuous transmission ; the nucleus for new 

 nuclei, the trophoplasts for new granules of all kinds accord- 

 ing to the needs of the plant. 



The author reviews the theories bearing on the question 

 from the so-called plastidules of Klsberg to the germ-plasma 

 of Weismann, and then applies his hypotheses ot lntra-cellu- 

 lar pangenesis to the different parts of a single plant and to 

 the transmission of peculiarities. The active particles recog- 

 nized in Darwin's hvpothesis he terms fangms, and, regard- 

 ing them as vehicles of hereditary characters, traces them 

 throughout their course. He is not obliged to ask tor any 

 means of transportation for these pangens, tor they work, so 

 to speak, on the spot. Thev are ready at hand at the points 

 of growth. We must look very sharply with reference to this 

 at two points of growth in the flowering plant, namely: the 

 bud and the seed. Each bud, with its growing point made up 

 of cells containing in their protoplasm the divisible granule, 

 carries with itselfallthe peculiarities which have been trans- 

 mitted without appreciable change. In the formation ot the 



