306 QUAETEllLY CHRONICLE OK MICROSCOPICAL SCIENCE. 



essentially distinct. In the vej;etative part of the stem the 

 formation of the leaves is the main object, ami the buds do 

 not arise till they have acquired a considerable size. In the 

 regiou of inflorescence the formation of buds becomes of 

 primary importance ; they increase in vigour and gradually 

 advance from' a lateral position to a position on the summit 

 of the stem near the median line. 



It has been supposed that abnormal formations such as 

 fasciations are due to a partition of the punctum vegetationis. 

 Warming, therefore, studied the development of Celosia 

 cristata and of Brassica oleracra var. botrytis. The first 

 developes its inflorescence like a Composite, with the only dif- 

 ference that its receptacle is irregular and compressed, and 

 the second by a very rapid formation of buds. But in neither 

 was there any trace of a partition of the vegetative point. 



The distinction of phyllomes from caulomes by morpho- 

 logically and genetically distinct characters is impossible. 

 They both arise from the peripheral tissues at a depth which 

 varies with the size they subsequently attain ; thus bracts 

 arise very often in the first layer of the periblem, while caulomes 

 hardly ever do so, but most usually in the third or fourth 

 layers. A distinctive character, perhaps, consists in the fact 

 that in the centre of phyllomes procambium cells originate 

 very rapidly^ and the tissue is consequently far from offering 

 the same regularity as the plerome of young caulomes. 



The majority of buds are axillary ; this is so uniform 

 that it has been regarded as the only normal one, and has 

 led to the supposition that the buds in all ebracteate inflores- 

 cences arise from a partition of the punctum vegetationis. 

 The causal nexus between the leaf and its axillary bud at 

 present remains unexplained. In their origin they are 

 always united at their base, and they may be, perhaps, 

 regarded as forming a whole of which the two constituent 

 portions have a diflerent morphological character according 

 to the role which they have to fill ; it is sometimes one, some- 

 times the other part of the double organ which is developed, 

 while in other cases both are in equilibrium. 



7. Perigynium of Carex. — Dr. McNab and W. T. Thiselton 

 Dyer contribute observations on this structure to the 

 ' Journ. Linn. Soc.,' xiv, 152 and ]54, which appear to 

 prove that it is a foliar organ, consisting of a bract alter- 

 nating with that which subtends the whole flower. 



8. Developtnent of Buds of Malaxis. — Prof. Dickie describes 

 in the ' Journ. Linn. Soc./ xiv, 180 — 182, the develop- 

 ment of the buds on the leaves of Malaxis. " The bodies in 

 ijuestion agree with the ovule in this : the nucleus appears 



