AT THE MICROSCOPE. 237 



equal number from next below that line. Placed on the slide in 

 this way, they tell their own tale. One may be shown with the 

 integument still attached ; it is necessary to remove it from the 

 others to show the sinuous lines, spines, etc. (where any of the 

 latter are present), clearly. I prefer them mounted dry. They 

 cockle much in drying, which is best prevented by placing them 

 between two slips of glass, on the upper of which a moderate 

 weight may be placed. Tuffen West. 



EXPLANATION OF PLATE XL. 



Fig. 1. — Represents the staminal column of one of the Malvaceae ; 

 perhaps Malope grandijiora, mag. 8 diam. The column appears 

 to have been cut open in the prej)aration of the specimen and 

 laid out flat. The anthers are unilocular (one-celled) and open 

 inwardly. The pollen is globular, with the outer coat granu- 

 lar and spiny. 



DraAvn by Tuffen West. 



-Sjnrideajilamentosa, mag. 18 diam., showing the " filaments " 

 and capsules, with the spores escaping therefrom. 



-Capsule of the same, mag. 50 diam. , showing the spores and 

 their mode of escape. 



-Delicately fringed branch. 



Drawn by H. M. J, Underbill. 



EXPLANATION OF PLATE XLI. 



Fig. 1. — Hydrachna globulus, natural size. 

 ,, 2. — The specimen exhibited on the slide of pupa, or '^ Leptus- 



form,'' mag. 10 diam. The young animal, in progress towards 



a higher phase, has been dissolved out by the action of potash. 



1.1; 2.2; 3.3; 4.4; indicate the first, second, third, and 



fourth pairs of limbs respectively ; I. , labium. 

 ,, 3. — Trophi as found in this specimen, mag. 100 diam. : m., the 



acute mandibles ; l.p. , I. p. , labial palpi. 

 ,, 4. — Claws and end of tarsus from the fore-leg of the first pair, 



and right side. 

 ,, 5. — The young larva in its free-swimming state. 

 ,, 6. — Hinder extremity of Ne^m ciiierea, with numerous examples in 



the attached parasitic condition of '^ Leptus-fona,'^ as shown 



in the slide. 

 ,, 7. — " Leptus-form," young Hydrachna being developed within it : 



p>., rudimentary palp ; 1.2.3.4., rudimentary, unsegmented 



limbs of the first, second, third, and fourth pairs respectively ; 



t, head of larva ; *, exuvium of its first pair of limbs still 



remaining attached ; g.o., genital orifice. 

 ,, 8. — Side-view of '"Leptiis-form," with included young Hydrachna. 

 ,, 9. — A further advanced condition ; the young animal about to 



make its escape as a free, active swimmer. 



Drawn by Tuffen West. 



