DEJPARTMENT OF BOTANICAL RESEIARCH. 59 



occupancy July i, 1909. The building comprises two main rooms for micro- 

 scopic and photographic work, a work-room, store-room, and dark-room ; it is 

 furnished with water and has an independent acetylene plant for light and 

 heat in the laboratory. The location on the brow of a hill facing to the 

 eastward, overlooking the valley of a tributary of the Carmel River, in which 

 the well-watered garden lies, is an ideal one for the experimentation in hand. 

 The grounds also include wooded slopes and hilltop area well suited for 

 dealing with wild plants. The representatives of the Carmel Development 

 Company have lost no opportunity to learn the needs of the Department and 

 have been quick to meet these needs voluntarily. 



CORRELATED INVESTIGATIONS. 



Alterations in Heredity Induced by Ovarial Treatment (by Dr. D. T. 

 MacDougal) : 



The study of the effects of the treatment of the ovarial apparatus of plants 

 with solutions of various chemical constituency, begun in 1905, has been 

 continued. Up to this time results have been obtained with species of Oeno- 

 thera, Raimannia, Carnegiea, and Penstemon; a large number of seedlings 

 representing experimentation with other genera are under observation. The 

 available results of these experiments, supported by those of Gager using 

 radium as an exciting agent and those of Tower in the application of 

 climatic factors, point indubitably to the conclusion that it is possible to 

 induce changes in germ-plasm whereby its transmission of hereditary char- 

 acters may be greatly altered. Some of the alterations take the form of 

 accentuated or strengthened fluctuations of qualities characteristic of the 

 plants treated, while in other cases the derivatives behave as mutants or newly 

 arisen forms. The fact that some of these have been cultivated successfully 

 to the fifth generation, without reversion or exhibition of pathological char- 

 acters, gives special importance to these results. 



The derivative of Oenothera biennis which was obtained early in the 

 investigation has been hybridized with its parent, with a result that the form 

 produced by the cross is more vigorous than either parent. Parental forms 

 and derivatives obtained by ovarial treatments are being grown in the various 

 acclimatization plantations to test their capacity for survival under different 

 conditions. As might be expected, their hardiness is not identical under the 

 various conditions into which they are thus thrown. 



No further theoretical explanation of the mechanism of such changes is 

 offered except that they may be induced in the germ-cells after the reduction 

 divisions have taken place and previous to fertilization. The alterations in 

 question may be induced in either the egg or sperm, a fact not yet determined, 

 and may consist in disturbances of the autolytic action of the cell, by which 

 catalytic processes are inhibited ; or the departure might be due wholly to the 



