NOTES AND ABSTRACTS. 



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Impatiens Holstii. By W. B. Hemsley tab. ^029 . 



Nat. ord. Geraniacea, tribe Balsamineo? ; E. Tropical Africa. Flowers 

 pure scarlet. If in. across. — G. H. 



Indigo-producing Substance in Indigo Plants, The Locali- 

 sation of the. By H. M. Leake (Ann. Bot. xix. April 1905, pp. 297- 

 309 ; one plate). — The author made a microscopic examination of the 

 tissues of several indigo-containing plants. He employed a sulphuric- 

 acetic-persulphate solution which precipitates the indigo in the cells of 

 the tissue as blue granules, and which at the same time acted as a fixing 

 agent. The material was then cut and stained in the usual way. 



Indujofera. — Various species were examined. In 7. sumatrana and 

 I. arrecta indigo was precipitated freely. The leaf showed it to be present 

 in all tissues except the xylem vessel?, not even excluding the epidermis 

 and guard-cells. In the rachi? it is present in the pith, cortex, and 

 phloem, and absent only in the xylem vessels and the lactiferous system. 

 The stem shows indigo only near the growing point : here it is deposited 

 in all elements except the xylem vessels and lactiferous cells. A small 

 quantity is present in the flowers. The roots show no indication of 

 indigo. 



Isatis tinctoria. — The main deposit in this plant occurs in the 

 mesophyll and veins of the lamina. In the epidermis precipitation also 

 occurs, especially in the guard-cells. The stem and flowers show no blue 

 coloration. 



Polygonum tinctorium. — The results of Molisch are confirmed, the 

 dye only occurring in the lamina of the young leaves. 



Phajus grandifolius, P. Wallichii, P. maculatus, as well as Calanthe 

 cestita and C. Veitchii, show abundant deposit in the parenchyma of the 

 mesophyll, xylem parenchyma, and guard-cells ; less is deposited in other 

 parts of the leaf, and none in the xylem vessels. Indigo is found through- 

 out the tissues of the pseudo-bulbs except the xylem vessels and raphide 

 cells. 



Strobilanthes flaccidifolius. — In the stem and leaf a deposit of indieo 

 is found in all the tissues except the xylem vessels. 



The author concludes by stating that it is impossible to accredit to 

 the chloroplasts any direct function in the production of the indigo- 

 forming substance. — A. D. C. 



Insect Injuries to Indian Corn. By S. A. Forbes (U.SA. Er, . 

 St7i. Illinois, Bull. 95, Nov. 1904 ; 5 plates (coloured) and 38 figs.). — 

 The bulletin opens with a general discussion of the injury caused by 

 insects to the corn, in the course of which it is pointed out that 

 " many insects will not thrive as well or multiply as rapidly on a vigorous, 

 quickly growing plant as on one in feeble condition.'' It is therefore 

 important that the cultivation should be of the best. In addition to this, 

 proper rotation of crops, timely ploughing and planting, the use of barriers 

 against the movement of destructive species from adjacent fields, combined 

 with insecticide measures, are the general points to be kept in view in 

 dealing with these injurious insects. The following insects are dealt with 

 in detail, others of less importance being mentioned in passing : — The 



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