SCIEXCE-GOSSIP. 



69 



liquor sanguinis itself, unable to evaporate and so 

 escape from under the cover, has a tendency to 

 produce a network and to dry into that form. The 

 white corpuscle, and under certain conditions the 

 common Amoeba and the Pelomyxa villosa, exhibit 

 reticulated structure. If the true structure of 

 protoplasm is not a reticulation, the certainty is 

 that animal protoplasm is pretty generally free to 

 assume that form. 



The network just referred to is of such extreme 

 minuteness and delicacy in the preparations which 

 I have examined, and it is so nearly colourless, 

 that some appreciable time must elapse, even 

 with a homogeneous immersion one-tenth, before 

 the eye can recognize it distinctly enough to 

 separate the meshes, and look down into the 

 interspaces. 



When the coarser threads of fibrin are in focus 

 with any objective from the one-fourth upward, 

 the red corpuscles will be slightly beyond the 

 focus, because the fibrin appears to have coagu- 

 lated in actual contact with the cover-glass, while 

 the corpuscles in the inverted drop have fallen to 

 the lowermost surface, and have there become 

 entangled within the net. If the objective, there- 

 fore, is very delicately sensitive to the collar 

 adjustment, the lens will not be properly adjusted 

 for the network on the cover and the red corpusles 

 on the lower surface of the capillary film, unless, as 

 the reader, of course, knows, a homogeneous- 

 immersion objective be used. The remark is 

 correct for a first-class dry lens like, for instance, 

 the superb one-fifth inch objectives by Spencer, 

 having respectively o 93 and 0-99 X.A. 



All these nets, even the most delicate, may be 

 used to advantage in studying the effect of the 

 collar movement. When the adjustment is as good 

 as possible, the filmy cobwebs will be visible with 

 a beauty and a brilliancy that cannot be put into 

 words. While the comparatively coarse threads 

 and clusters may be observable with improper 

 adjustment, with the correct position of the lenses 

 those same threads will glitter like filaments and 

 skeins and webs of polished silver. With the 

 collar purposely thrown out of adjustment the 

 objects may still be visible, but so dull and dead, 

 and misty a vision of what they 

 were at th'r best, that the lesson must 



be of value to the eye of even the accomplished 

 amateur. The comparatively huge masses of dis- 

 integrated white corpuscles share in the brilliant 

 beauty, or in the lifeless dulncss, as the collar 

 Improperly placed. Under a 

 fifth, like those of N A. fig 93 

 and fig. 99 by Spcnc/rr, the correct adjustment 

 produces a picture whose delicate Inns and 

 minut" -parks and 



threads of living -.ilver With incorrect adju-.t 

 rsenl, or without the Ixvit, the mim. 



is invisible, except perhaps as dull little bits of 

 shapeless film scattered here and there among 

 the red corpuscles. It is not possible with my 

 dry objectives, which have been mentioned here, 

 to separate these delicate filaments unless the collar 

 has been placed exactly right, when they become 

 as brilliantly refractive as the more robust threads, 

 and as the crushed and broken colourless corpus- 

 cles, whose scattered fragments themselves sparkle 

 and glitter. 



The same slide may be used to give the micro- 

 scopist somewhat of a surprise unless he is already 

 familiar with the flatness, or the absence of flatness, 

 in the field of his best objectives. With Spencer's 

 one-fifth N.A. 0-99 the field is "unflat," if there is 

 such a word, except as a little round spot in the 

 middle, yet the objective, as a result of the 

 optician's art, is as nearly perfect as it is possible 

 to produce, and its definition and its resolving 

 power can be described only by the words, 

 magnificent, marvellous, and their colloquial 

 synonyms. With his one-fifth N.A. 093 these 

 qualities are much less brilliant, yet the field is 

 flatter, or rather, it shows a greater surface of 

 flatness at the same time ; the effect of its 

 smaller aperture. 



527, Monmouth Street, Trenton, 



Sew Jersey, U.S.A.; July 2nd, 1897. 



BOTANICAL NOTES. 



A MONG a number of commoner plants which 

 1 ■*■ have been sent for identification during 

 the past month we may note : the Rev. W. W. 

 Mason has sent us the alien Sisymbrium pannonicitm, 

 Jacq., from Crosby, Lanes. Mr. T. Brewster sends 

 Geranium lancastriense, With., from Walney Island. 

 Mr. White sends us Polentilla hirta, Linn., from a 

 field near Montpellier House, Budleigh Salterton, 

 Devon. The Kev. Vere F. Willson, of Fulbeck 

 Rectory, Grantham, sends us Orobanche clatior, 

 Sutton, from the Lincoln Heath. It is a native, 

 but very rare in Lincolnshire. Erysimum pcrfoliatum, 

 Crantz., is growing in a mangel-wurzel field at 

 Cadney, Brigg. No doubt if allowed to seed it 

 would be permanent, like E. cheiranthoitks, Linn., 

 which is found all over the fenland now, but is 

 quite a late introduction in Lincolnshire. It 

 was not recorded for the county till 1872. We 

 hear from the Kev, K W. Goodall, that he took 

 Trigontlla purpuraseens, Lam., on Lincoln Heath, 

 on July 2nd. This is a new record for the 

 county. 



I.ai 1. MlDSUMMI ' .1 "V. 1 11 Mr. A. 1 1. Swin , 



Clovernook, Southampton, writes. "The smallei 

 oaks and beeches in the Ml I on 1 line now, ,11 

 il..- . oinmeiK ' -mi ni >■( | • 1 1 -, , put foi th fresl 



,1 ;i ,. , ..ml print: had ai rived 



