August 29, 1902.] 



SCIENCE. 



347 



of Isotoma and Xenylla. They burrow as the 

 tide rises. lu the outer middle beach is 

 found the debris left at high tide, and this 

 is feasted upon by scavengers, these scaven- 

 gers in turn by predaceous forms of vari- 

 ous orders of strength and swiftness. The 

 tip of the sandspit is a region of currents 

 where lamellibranchs thrive, attached to 

 and protecting masses of Spartina. The 

 inner beach supports numerous fiddler 

 crabs. The animals form a society, the 

 members of which are all there for some as- 

 signable purpose. The paper closed with a 

 discussion of an auxiliary theory of adapta- 

 tion, called segregation in the fittest en- 

 vironment. 



Observations on the Mouth Structure of 

 Scale Insects: John B. Smith, Rutgers 

 College. (Will appear in full in Bull. 

 159, N. J. Experiment Station.) 

 - The mouth parts of scale insects have 

 been figured as three slender bristles or 

 lancets for the adult and as a looped struc- 

 ture for the larva. The three bristles are 

 regarded as mandibles and united maxillse ; 

 but the nature or use of the larval loop has 

 not been explained so far as the author's 

 literature could inform him. The author 

 regards all the bristles as maxillary and 

 finds that the loop is used as a reserve 

 length of tubing to keep the insect at all 

 times in touch with its food. The bristles 

 pass beneath the galear remnant and, form- 

 ing a loop, return through a chitinous tube 

 in the galea and are then forced into the 

 plant tissue. The specimens studied were 

 mostly prepared and mounted by Mr. E. L. 

 Dickerson in securing material for a gradu- 

 ation thesis. (Discussed by Messrs. Mar- 

 latt, Mark, Webster, Osborn and Needham. ) 



Early Development of the Rock Barnacle, 

 Balanus: M. A. and Anna N. Bigei.ow, 

 Columbia University. (In the absence 

 of authors, read by title.) 



The authors described the early develop- 

 ment of rock-barnacle, Balanus, dealing 

 primarily with the subject from a stand- 

 point of cell-lineage. Contrary to previous 

 accounts, they maintain that the cleavage 

 is regiilar and determinate. The germ- 

 layers are traced from the early stages of 

 the cleavage, and the development is shown 

 to be closely similar to that of barnacles of 

 the genus Lepas. 



AFTERNOON SESSION, JULY 3. ' PROFESSOR E. 

 L. MARK IN THE CHAIR. 



Wind and Storms as Agents in the Diffu- 

 sion of Insects: Francis M. Webster, 

 Wooster, 0. (Will appear in full in the 

 American Naturalist.) 

 The speaker called attention to the sev- 

 eral influences of winds on the diffusion 

 of insects both independently of and in 

 connection with thunder-storms. (Dis- 

 cussed by Messrs. J. B. Smith, Surface, 

 Minot, Dyche and Bowlus.) 



The Blind Fish of Cuba (with lantern 



slides) : Carl H. Eigenmann. 



There are two species of blind fish found 

 in the sink holes leading down to the under- 

 ground streams draining to the south be- 

 tween Artemisa, Province Pinar del Rio and 

 Alacranes, Province Matanzas. These fish 

 are immigrants from the sea. They are 

 viviparous; the young are about an inch 

 long and four in number per gestation. 

 The unborn young and the recently born 

 individuals are colorless and possess well- 

 developed but small eyes. The fish acquire 

 color with age and the eyes very probably 

 degenerate : at least they become covered 

 with a thick layer of tissue. (Discussed by 

 Professor Surface.) 



Tlie Problem of Getting Air, and How it is 

 Solved by Aquatic Insects (with lantern 

 slides) : James G. Needham, Lake For- 

 est College. 

 The primitive terrestrial insect, with its 



