Adriamycin is one of the best antibiotics of the anthracycline class very recently introduced in cancer chemotherapy.Even though its pharmacological and bio chemical aspects are known at present , the details of the cytological damages which this drug causes have not been sufficiently investigated.Some adverse side effects which the drug causes in the recipients, pose serious health problems (See Carter 1975). Hence a detailed investigation on the cytological effects of the drug was undertaken using the 'Allium test' of Levan (1949). The treatments were so timed that data on the chronobiological effects of the drug can be used by physicians in the administration of the drug more efficiently. Materials and methodsRooted bulbs of the common onion Allium cepa (2n=16) were used for studying the cytological effects of adriamycin.As Allium cepa is a material in which occurs a small amount of natural aberra tions, screening was done for getting bulbs, which were free of any natural aberra tions. These selected bulbs were grown in pots containing sand. When the roots were about 1-1.5cm long, the bulbs were removed from the soil, washed well with water and the root systems kept in cavity blocks containing 3 different concentrations -0 .1%, 1% and 10% of adriamycin (Adriablastina of Farmitalia) in distilled water.In order to assess the effect of the drug at different stages of mitotic cycle, materials were treated for specific periods of time as 12 noon to 3P.M., 3P.M. to 6P.M., 3P.M. to 9P.M., 3P.M. to 12 midnight, 3P.M. to 3A.M., 3P.M. to 3P.M. (24 hours).The treatments were done in duplicate. Materials of one series were fixed soon after the treatment (designated as A batch). In the second series the bulbs were throughly washed in water (immediately after treatment and transferred to distilled water and fixed at a common time, 1-30 P.M. (designated as B batch), for harvesting the maximum number of cells in metaphase and anaphase stages and for studying the degree of recovery from drug effects.Fixing was done in Carnoy's fluid. In order to make cytological preparations, the root tips were hydrolysed in 1:1 mixture of concentrated hydrochloric acid and ethyl alcohol and then squashed in acetocarmine stain. Photomicrographs were prepared from fresh preparations.

Although the endosperm of Haemanthus katherinae has been extensively used in the studies on dynamic and ultrastructural aspects of mitosis (Bajer and Mole-Bajer 1972), its cytological constitution has been escaping careful investi gation. Spontaneous abortion of fruits at varying stages of maturity is a common feature in this horticultural species. Hence an exploration into the cytology of the endosperm in developing and also degenerating fruits of Haemanthus katherinae was undertaken and the results are summarised in this paper. ObservationsSerial microtome sections revealed that the endosperm of Haemanthus katherinae followed unclear type of development.The free nuclear stage lasted for upto 9 days after pollination and then the endosperm gradually became cellular, cell wall formation proceeding from the periphery towards the central liquid endosperm. In the free nuclear stage the nuclei were of almost uniform size and underwent synchronous mitoses. On the other hand in the cellular endosperm the nuclei were highly variable in size. This became more evident as the endosperm matured. The interior part of the endosperm showed more drastic variations in nuclear size than the peripheral part. There was considerable increase in the average diameter of nuclei with advancing maturity of the endosperm as data in Table 1 reveal.Chromosome counts made from acetocarmine squash preparations showed that the endosperm of Haemanthus katherinae is basically triploid (3n=27) in 1 Extracted from Ph. D. thesis, University of Kerala.

The endosperm serves as the main source of nutrition for the developing embryo and its failure results in the abortion of embryo and consequently low fertility. Economically, the tissue is of great importance since it is the store house of carbohydrates, proteins, lipids and growth regulating substances. Although much work has been done on the morphology and physiology of this tissue in a number of angiosperms, the record of cytological investigations on this is relatively meagre. The very interesting findings made on the cytology of coconut endo sperm in this laboratory (Abraham 1963, Abrahm and Mathew 1963, Abraham , Ninan and Gopinath 1965, 1966) gave inspiration to inquire into the cytological situations in the endosperm of allied genera. The observations made on the cytology of the endosperm in Palmyrah palm (Borassus flabellifer Linn.) are presented in this paper. Material and methodsThe endosperm for the present work was collected from palmyrah palms from a few localities in Trivandrum District. Endosperm at various stages of develop ment was fixed in Carnoy's fluid in the noon hours and after a few changes of fixative acetocarmine smears were made.The liquid endosperm found in the central cavity of the developing seeds was sucked out using hypodermic needle and to it was added Carnoy's fluid and then it was subjected to centrifugation at 250rpm for two hours. The sediment was again fixed in Carnoy's fluid and acetocarmine smears were made.In order to study the development of the endosperm 1 to 20 week old intact seeds were fixed in F . A. A. and microtome sections were made by the usual paraffin method. The slides were stained with iron haematoxylin and fast green.To ascertain the chromosome number of Borassus flabellifer Linn. growing em bryos from 4 to 5 month old nuts were fixed in Carnoy's fluid in the noon hours and acetocarmine smears were made. ObservationsThe chromosome number of the species was ascertained as 2n (2x)=36 (Fig. 1). The earliest recognizable stage in endosperm development is the occurrence of

Trad 02, a clone derived from a natural hybrid of Tradescantia occidentalis and T. canaliculata is especially noted for very low seed set. Meiotic abnormalities

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