40 THE AEEANGEMENT OF THE 



nucleus, after a few minutes, may disappear again, and a net-work be 

 reestablished, where shortly before there was a compact lump. Sometimes 

 round bodies looking like "nuclei jump forth from the interior of the blood- 

 corpuscle, and float freely in the surrounding fluid. Sometimes protruded 

 flaps become pediculated, and shortly afterward, through breakage of the 

 pedicle, a pale body is separated from the original blood-corpuscle. Some- 

 times the protoplasmic body itself is becoming constricted on different parts 

 of its bulk, and such constrictions may terminate in a separation of smaller 

 lumps from the original body. On some of these lumps, even the net-like 

 structure of the protoplasm is still visible. Thus a larger blood-corpuscle 

 may be divided into smaller lumps of different shapes. 



After from one to two hours' observation, the majority of the blood- 

 corpuscles, in part considerably decreased in size through repeated divisions, 

 swell up and are provided with large vacuoles and large, structureless flaps. 

 In this condition the net-work in the protoplasm is evidently broken apart, 

 inasmuch as the granules are no longer connected with each other, but float 

 in the interior of the protoplasm in a sort of motion, for which the term 

 "molecular motion" has been adopted. Lastly, such a swelled protoplasmic 

 body bursts, and the granules are spread in the surrounding fluid, and with 

 this complete death of the blood-corpuscle has ensued. Blood-corpuscles of 

 perfectly fresh oysters die after having been kept for about two hours under 

 the microscope, whereas those from oysters which have been kept out of the 

 sea for a couple of days die much sooner and more rapidly. 



THE STRUCTURE AND GROWTH OF SOME FORMS OF MILDEW. BY WILLIAM 

 HASSLOCH, M. D., OF NEW YORK.* 



During researches in which I stained the corneas of dogs and cats with 

 chloride of gold, many of my preparations became mouldy, and, as repeated 

 application of the chloride produced well-marked characteristic violet colora- 

 tion of the mildew, I succeeded in studying its intimate structure. 



The application of one-half per cent, solution of chloride of gold, for 

 from one to six hours, sufficed to stain the parasitic growth from a light-red 

 violet to a dark blue. The preparations were mounted in the common way, 

 in a mixture of distilled water with glycerine, and remained unchanged for 

 months. 



With a magnifying power of 500, thallus-threads (mycelia), hyphse, and 

 conidia could be seen, as well as numerous branching chains of conidia, all 

 united with mycelia. These formations appear finely granular. Many of the 

 granules are not round, but look jagged and pointed ; moreover, both the 

 hyphse and mycelia-threads show, on their periphery, accumulations of 

 minute, generally dark violet, partly pediculated granules, to such an extent 

 as to conceal, in some places, the contours of the plant. For greater ampli- 

 fication I used an immersion-lens of Tolles, with a power of 1200 diameters, 

 and immersion-lenses of Verick. With these the mycelia, mostly uncham- 



* New York Medical Journal, November, 1878. 



