1900] MICROSCOPICAL JOURNAL. 236 



wingB, petals, leaves, etc., may generally be kept in place 

 merely by tbe pressure of the cover-glass. Very minute 

 objects, such as pollen grains for instance, are made to 

 adhere by means of a thin film of very weak gum, which 

 is placed on the slide and allowed to dry. Breathing upon 

 the slide will then moisten the film of gum sufficiently to 

 cause the pollen to adhere when placed thereon. In every 

 case, however, it is of the utmost importance that the gum 

 and gold-size should be allowed to dry thoroughly before 

 the Cover-glass is put on, or the remaining moisture will 

 settle on the under side of the cover-glass, and utterly 

 spoil the slide. A final ring of gold-size is then run on, 

 and this last should be allowed to dry until it is just sticky 

 only, when the cover-glass may be gently lowered into 

 place by means of a pair of forceps, and the edges press- 

 ed gently down.care being taken that the cover-glass ad- 

 hers all round its edges. Finally, the slide is finished by 

 a coat of Brunswick Black over all, and just covering the 

 edge of the cover-glass. 



The Richmond Park Ponds. — I am glad to see atten- 

 tion drawn to these ponds and pools, as, personally, I have 

 found them especially productive in one branch of Pond 

 Life, Freshwater Algae. To mention the alga) to be found 

 here, would be to enumerate the chief forms of these 

 plants. They occur in the Pen ponds and smaller ponds 

 and pools. As regards other forms of Pond Life, I have 

 met with Hydra of a dull brown color, and also of a rich 

 orange-buflF. That particular condition of Euglena, dur- 

 ing which the individuals are aggregated together and 

 are invested with cellulose cell-walls through which they 

 break away, sometimes forms a thick grey-green scum on 

 the surface of the Pen ponds. From what I have seen 

 when collecting AlgsB, it would appear that the ponds and 

 pools of Richmond Park would well repay systematic in- 

 vestigation in all branches of Pond Life. In conclusion* 

 it will be of interest to mention, that in the neighborhood 



