36 On the Microscopical Examination ['''joumL "iTrisTo!' 



of dispute, and much has heen -written on the subject. Many- 

 authors have held that this substance -which joined the cell-walls 

 together formed on the free surface of the plant what we call the 

 cuticle, and therefore considered that the cuticle and intercel- 

 lular substance were identical. There does not, however, seem to 

 be any intercellular substance, what has been described as inter- 

 cellular substance being an altered condition of the primary cell- 

 wall. The cuticle, on the other hand, is a thickening layer found 

 on the outside of the cell-wall, and in this respect similar to the 

 Extine of the pollen grain and the Exosporium. The use of the 

 carmine staining solution shows this very conclusively, as the cuticle 

 can be very easily stained, while the so-called intercellular substance 

 remains intact. Ha-sdng thus briefly discussed a few of the more 

 important points to be attended to in the examination of the cell 

 and cell-wall, we shall in our next proceed to the examination of 

 the Protoplasm, Nucleus, and Cell-sap. 



(To be continued.) 



VII. — On the Microscopical Examination of Milk under certain 

 Conditions. By J. B. Dancer, F.K A.S. 



In August and September last an account appeared in one of the 

 newspapers (and also in other periodicals), which had been copied 

 from the 'Journal des Connaissances Medicales,' of some micro- 

 scopical observations made by M. Y. Essling on Milk, in which the 

 author stated that " if the surface of fresh cream be examined under 

 the lens, one perceives, amid myriads of milky and fatty globules, 

 a number of either round or oblong corpuscles, sometimes accom- 

 panied with finely dotted matter, being neither more nor less than 

 germinative masses of vibrios — just what is seen in most substances 

 in a state of putrefaction In summer these corpuscles make their 

 appearance within fifteen or twenty-four hours after milking; in 

 winter they will be perceptible after the lapse of two or three days. 

 If the observation be continued until the moment of coagulation we 

 see these corpuscles increase in number, bud, form ramified chains, 

 and at length be transformed into regular mushrooms or filaments 

 composed of cells placed end to end in simple series, and supporting 

 at their extremities a spherical knob filled with granulous matter. 

 M. V. Esshng thinks that they may be classified among the Asco- 

 phora. But the important point is, that the first appearance of 

 these spores occurs before the milk gets sour, and as this substance is 

 almost the exclusive aliment of children, there is reason to suppose 

 that many of the gastric afi'ections to which they are subject are* 



