﻿28 
  JOURNAL 
  OF 
  the: 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOL. 
  12, 
  NO. 
  2 
  

  

  ding 
  to 
  the 
  interior 
  prevents 
  that 
  proHfic 
  asexual 
  reproduction 
  by 
  

   budding 
  and 
  fission, 
  by 
  parthenogenesis, 
  or 
  by 
  polyembryony 
  always 
  

   present 
  in 
  those 
  groups 
  in 
  which 
  parasitism 
  is 
  a 
  prevalent 
  condition; 
  

   and 
  (4) 
  the 
  almost 
  complete 
  absence 
  of 
  attached 
  forms 
  which, 
  except 
  

   for 
  secondarily 
  attached 
  molluscs, 
  are 
  found 
  only 
  among 
  the 
  brachio- 
  

   pods 
  and 
  the 
  tunicates. 
  

  

  The 
  annelids, 
  in 
  addition 
  to 
  their 
  dominant 
  external 
  segmentation, 
  

   also 
  possess 
  a 
  coelome, 
  but 
  this 
  becomes 
  greatly 
  reduced 
  in 
  the 
  crusta- 
  

   ceans 
  and 
  insects. 
  In 
  the 
  echinoderms, 
  however, 
  the 
  curious 
  distortion 
  

   leads 
  to 
  a 
  relatively 
  considerable 
  average 
  length 
  for 
  each 
  of 
  the 
  five 
  

   segments 
  represented, 
  and 
  with 
  this 
  annelidan 
  feature 
  the 
  coelome 
  

   reappears 
  in 
  a 
  highly 
  perfected 
  form. 
  

  

  The 
  development 
  of 
  the 
  annelids 
  indicates 
  a 
  very 
  close 
  relationship 
  

   with 
  the 
  molluscs. 
  These 
  two 
  groups 
  thus 
  carry 
  onward 
  the 
  essential, 
  

   differences, 
  as 
  well 
  as 
  the 
  essential 
  similarities, 
  between 
  the 
  cestodes 
  

   and 
  the 
  trematodfes. 
  Similarly 
  the 
  arthropods 
  and 
  the 
  echinoderms 
  

   appear 
  to 
  be 
  structurally 
  parallel 
  to 
  the 
  nemerteans, 
  phoronids, 
  

   brachiopods 
  and 
  chaetognaths, 
  the 
  former 
  representing 
  the 
  cestode- 
  

   annelid, 
  the 
  latter 
  the 
  trematode-priapulid-sipunculid-moUusc 
  type. 
  

  

  The 
  enteropneusts, 
  the 
  tunicates, 
  the 
  cephalochodates 
  {Amphioxus, 
  

   etc.) 
  and 
  the 
  vertebrates 
  are 
  quite 
  unrepresented 
  in 
  the 
  externally 
  

   segmented 
  line, 
  which 
  culminates 
  in 
  the 
  arthropods 
  and 
  echinoderms. 
  

   They 
  differ 
  from 
  all 
  other 
  animals 
  in 
  the 
  possession 
  of 
  gill 
  slits 
  or 
  pores. 
  

   These 
  structures 
  represent 
  the 
  final 
  step 
  in 
  the 
  organization 
  and 
  

   centralization 
  of 
  the 
  respiratory 
  function 
  and 
  its 
  connection 
  with 
  the 
  

   endoderm. 
  This 
  is 
  obviously 
  a 
  minor 
  structural 
  detail, 
  presumably 
  

   of 
  late 
  origin, 
  and 
  as 
  such 
  it 
  suggests 
  that 
  while 
  the 
  other 
  major 
  

   animal 
  types 
  probably 
  all 
  appeared 
  almost 
  or 
  quite 
  simultaneously 
  

   the 
  evolution 
  of 
  the 
  forms 
  with 
  gill 
  apertures 
  was 
  considerably 
  delayed. 
  

  

  GEOPHYSICS. 
  — 
  The 
  latitude 
  of 
  Ukiah 
  and 
  the 
  motion 
  of 
  the 
  pole.'^ 
  

   Walter 
  D. 
  Lambert, 
  U. 
  S. 
  Coast 
  and 
  Geodetic 
  Survey. 
  

   In 
  January, 
  1921, 
  Professor 
  A. 
  C. 
  Lawson 
  of 
  the 
  University 
  of 
  

   California 
  published 
  an 
  article 
  on 
  earth 
  movements 
  in 
  California.^ 
  

  

  1 
  Presented 
  before 
  the 
  Philosophical 
  Society 
  of 
  Washington, 
  November 
  19, 
  1921. 
  Re- 
  

   ceived 
  December 
  7, 
  1921. 
  The 
  substance 
  of 
  this 
  paper 
  was 
  also 
  presented 
  at 
  a 
  meeting 
  

   of 
  the 
  American 
  Astronomical 
  Society 
  at 
  Swarthmore, 
  Pa., 
  December 
  29, 
  1921. 
  This 
  

   paper 
  is 
  based 
  on 
  a 
  longer 
  article 
  by 
  the 
  author 
  entitled 
  An 
  investigation 
  of 
  the 
  latitude 
  of 
  

   Ukiah, 
  California, 
  and 
  of 
  the 
  motion 
  of 
  the 
  Pole, 
  which 
  will 
  appear 
  as 
  a 
  Special 
  Publication 
  

   of 
  the 
  U. 
  S. 
  Coast 
  and 
  Geodetic 
  Survey. 
  

  

  ^ 
  The 
  mobility 
  of 
  the 
  Coast 
  Ranges 
  of 
  California, 
  an 
  exploitation 
  of 
  the 
  elastic 
  rebound 
  

   theory. 
  Univ. 
  Calif. 
  Publ., 
  Bull. 
  Dept. 
  Geol. 
  12: 
  No. 
  7. 
  Jan. 
  11, 
  1921. 
  

  

  